Besides his interest in philosophy, Fodor followed opera and regularly wrote columns for the London Review of Books on that and other topics. Fodor's first marriage was to the applied psychologist Iris Goldstein,
with whom he had one son. After their divorce, he married the linguist Janet Dean. Janet and he lived in Manhattan and had a daughter. He died at home on November 29, 2017.
Philosophical work
Fodor argued in his 1975 book The Language of Thought that mental states, such as beliefs and desires, are relations between individuals and mental representations. He maintained that these representations can only be correctly explained in terms of a language of thought (LOT) in the mind. Furthermore, this language of thought itself is an actually existing thing that is codified in the brain and not just a useful explanatory tool. Fodor adhered to a species of functionalism, maintaining that thinking and other mental processes consist primarily of computations operating on the syntax of the representations that make up the language of thought.
For Fodor, significant parts of the mind, such as perceptual and linguistic processes, are structured in terms of modules,
or "organs", which he defines by their causal and functional roles.
These modules are relatively independent of each other and of the
"central processing" part of the mind, which has a more global and less
"domain specific" character. Fodor suggests that the character of these
modules permits the possibility of causal relations with external
objects. This, in turn, makes it possible for mental states to have
contents that are about things in the world. The central processing
part, on the other hand, takes care of the logical relations between the
various contents and inputs and outputs.
Although Fodor originally rejected the idea that mental states
must have a causal, externally determined aspect, in his later years he
devoted much of his writing and study to the philosophy of language because of this problem of the meaning and reference of mental contents. His contributions in this area include the so-called asymmetric causal theory of reference and his many arguments against semantic holism. Fodor strongly opposed reductive accounts of the mind. He argued that mental states are multiple realizable
and that there is a hierarchy of explanatory levels in science such
that the generalizations and laws of a higher-level theory of psychology
or linguistics, for example, cannot be captured by the low-level
explanations of the behavior of neurons and synapses. He also emerged as
a prominent critic of what he characterized as the ill-grounded Darwinian theories of natural selection as an explanation of mind.
Fodor and the nature of mental states
The structure of a mental state, such as that an individual called Mary believes that a man has bitten a dog, as described by Rudolf Carnap, Gottlob Frege, and Fodor. Fodor's scheme says that a person's attitude to something makes use of a mental representation of that thing.
Despite the changes in many of his positions over the years, Fodor's idea that mental states embodying intentionality, propositional attitudes, like beliefs and desires are relational never changed. He attempted to show how mental representations, specifically sentences in the language of thought,
are necessary to explain this relational nature of mental states. Fodor
considers two alternative hypotheses. The first denies the relational
character of mental states, while the second considers mental states as
two-place relations. The latter position can be further subdivided into the Carnapian view that such relations are between individuals and sentences of natural languages, and the Fregean view that they are between individuals and the propositions expressed by such sentences. Fodor's own position, instead, is that to properly account for the
nature of intentional attitudes, it is necessary to employ a three-place relation between individuals, representations and propositional contents.
Considering mental states as three-place relations in this way, representative realism
makes it possible to hold together all of the elements necessary to the
solution of this problem. Further, mental representations are not only
the objects of beliefs and desires, but are also the domain over which
mental processes operate. They can be considered the ideal link between
the syntactic notion of mental content and the computational notion of functional architecture. These notions are, according to Fodor, our best explanation of mental processes.
Functional architecture of the mind
Psychological nativism and modularity
The Müller-Lyer illusion,
that two identical lines look to be of differing lengths, even if the
subject knows they are the same length, persuaded Fodor that mental
processes are grouped in discrete modules without access to each other.
Following in the path paved by linguistNoam Chomsky, Fodor developed a strong commitment to the idea of psychological nativism. Nativism postulates the innateness of many cognitive functions and
concepts. For Fodor, this emerges naturally out of his criticism of behaviourism and associationism. These criticisms led him to formulate his hypothesis of the modularity of the mind.
Fodor noted the evidence from perceptual errors like the Müller-Lyer illusion
that processes such as visually estimating the length of a line are not
interfered with by the knowledge that the two lines are actually the
same length. He took this to mean that the visual processes were in a
separate module from knowledge.
The idea can be traced back to the 19th century phrenology movement. Its founder Franz Joseph Gall
claimed that mental faculties were associated with specific regions of
the brain. Hence, someone's level of intelligence, for example, could be
"read off" from the size of a particular bump on his posterior parietal lobe. This simplistic view of modularity has been disproven in the 20th century.
Fodor revived the idea of modularity, without the notion of
precise physical localizability, in the 1980s, and became a vocal
proponent of it with the 1983 publication of his monographThe Modularity of Mind, where he points to Gall through Bernard Hollander's In search of the soul. Two properties of modularity, informational encapsulation and domain specificity,
make it possible to relate functional architecture to mental content. A
person's ability to elaborate information independently from their
background beliefs allows Fodor to give an atomistic
and causal account of mental content. The main idea is that the
properties of the contents of mental states can depend, not just on the
internal relations of the system of which they are a part, but also on
their causal relations with the external world.
Adoption by cognitive and evolutionary psychologists
Fodor's
notions of mental modularity, informational encapsulation and domain
specificity were taken up and expanded, much to Fodor's chagrin, by
cognitive scientists such as Zenon Pylyshyn and evolutionary psychologists such as Steven Pinker and Henry Plotkin.Fodor complained that Pinker, Plotkin and other members of what he
sarcastically called "the New Synthesis" had taken modularity and
similar ideas way too far. He insisted that the mind is not "massively
modular" and that, contrary to these researchers, the mind was a long
way from having been explained by the computational, or any other, model. The main reason for this is that most cognition is abductive and global, hence sensitive to all possibly relevant background beliefs to (dis)confirm a belief. This creates the frame problem
for the computational theory, because the relevance of a belief is not
one of its local, syntactic properties but context-dependent.
Intentional realism
In A Theory of Content and Other Essays
(1990), Fodor takes up another of his central notions: the question of
the reality of mental representations. He sought to justify
representational realism, so as to justify the idea that the contents of
mental states are expressed in symbolic structures such as those of the
LOT.
Fodor's criticism of Dennett
Fodor starts with some criticisms of so-called standard realism.
This view is characterized, according to Fodor, by two distinct
assertions. One of these regards the internal structure of mental states
and asserts that such states are non-relational. The other concerns the
semantic theory of mental content and asserts that there is an isomorphism
between the causal roles of such contents and the inferential web of
beliefs. Among modern philosophers of mind, the majority view seems to
be that the first of these two assertions is false, but that the second
is true. Fodor departs from this view in accepting the truth of the
first thesis but rejecting strongly the truth of the second.
In particular, Fodor criticizes the instrumentalism of Daniel Dennett. Dennett maintains that it is possible to be realist with regard to
intentional states without having to commit oneself to the reality of
mental representations. Now, according to Fodor, if one remains at this level of analysis, then there is no possibility of explaining why the intentional strategy works:
There is ... a standard objection
to instrumentalism ...: it is difficult to explain why the psychology of
beliefs/desires works so well, if the psychology of beliefs/desires is,
in fact, false.... As Putnam, Boyd and others have emphasized, from the
predictive successes of a theory to the truth of that theory there is
surely a presumed inference; and this is even more likely when ... we
are dealing with the only theory in play which is predictively
crowned with success. It is not obvious ... why such a presumption
should not militate in favour of a realist conception ... of the
interpretations of beliefs/desires.
Productivity, systematicity and thought
Building on Chomsky
Fodor also has positive
arguments in favour of the reality of mental representations in terms
of the LOT. He maintains that if language is the expression of thoughts
and language is systematic, then thoughts must also be systematic. Fodor
draws on the work of Noam Chomsky to both model his theory of the mind and to refute alternative architectures such as connectionism. Systematicity in natural languages was explained by Chomsky in terms of two more basic concepts: productivity and compositionality.
Productivity is a representational system's unbounded ability to
generate new representations from a given set of symbols, using its cognitive architecture. "John", "loves", and "Mary" allow for the construction of the sentences "John loves Mary" and "Mary loves John". Fodor's language of thought
theorizes that representations are decomposable into constituent parts,
and these decomposed representations are built into new strings.
More important than productivity is systematicity since it does
not rely on questionable idealizations about human cognition. The
argument states that a cognizer is able to understand some sentence in
virtue of understanding another. For example, no one who understands
"John loves Mary" is unable to understand "Mary loves John", and no one
who understands "P and Q" is unable to understand "P". Systematicity
itself is rarely challenged as a property of natural languages and
logics, but some challenge that thought is systematic in the same way
languages are. Still others from the connectionist tradition have tried to build non-classical networks that can account for the apparent systematicity of language.
The fact that systematicity and productivity depend on the
compositional structure of language means that language has a
combinatorial semantics. If thought also has such a combinatorial semantics, then, Fodor stated, there must be a language of thought.
Formalizing thought processes
The
second argument that Fodor provides in favour of representational
realism involves the processes of thought. This argument touches on the
relation between the representational theory of mind
and models of its architecture. If the sentences of Mentalese require
unique processes of elaboration then they require a computational
mechanism of a certain type. The syntactic notion of mental
representations goes hand in hand with the idea that mental processes
are calculations which act only on the form of the symbols which
they elaborate. And this is the computational theory of the mind.
Consequently, the defence of a model of architecture based on classic
artificial intelligence passes inevitably through a defence of the
reality of mental representations.
For Fodor, this formal notion of thought processes also has the
advantage of highlighting the parallels between the causal role of
symbols and the contents which they express. In his view, syntax plays
the role of mediation between the causal role of the symbols and their
contents. The semantic relations between symbols can be "imitated" by
their syntactic relations. The inferential relations which connect the contents of two symbols can be imitated by the formal syntax rules which regulate the derivation of one symbol from another.
The nature of content
From
the beginning of the 1980s, Fodor adhered to a causal notion of mental
content and of meaning. This idea of content contrasts sharply with the inferential role semantics
to which he subscribed earlier in his career. Fodor went on to
criticize inferential role semantics (IRS) because its commitment to an
extreme form of holism excludes the possibility of a true naturalization of the mental. But naturalization must include an explanation of content in atomistic and causal terms.
Anti-holism
Fodor, while following W.V.O. Quine's confirmation holism, criticised semantic holism, the idea that every connection of a concept is part of its meaning. The identity of the content of a mental state, under semantic holism, can only be determined by the totality of its epistemic bonds. Fodor argued that this makes the realism of mental states an impossibility:
If people differ in an absolutely
general way in their estimations of epistemic relevance, and if we
follow the holism of meaning and individuate intentional states by way
of the totality of their epistemic bonds, the consequence will be
that two people (or, for that matter, two temporal sections of the same
person) will never be in the same intentional state. Therefore, two
people can never be subsumed under the same intentional generalizations.
And, therefore, intentional generalization can never be successful.
And, therefore again, there is no hope for an intentional psychology.
The asymmetric causal theory
Having
criticized the idea that semantic evaluation concerns only the internal
relations between the units of a symbolic system, Fodor can adopt an externalist
position with respect to mental content and meaning. For Fodor, later
in his life, the problem of naturalization of the mental is tied to the
possibility of giving "the sufficient conditions for which a piece of
the world is relative to (expresses, represents, is true of) another
piece" in non-intentional and non-semantic terms. If this goal is to be
achieved within a representational theory of the mind, then the
challenge is to devise a causal theory which can establish the
interpretation of the primitive non-logical symbols of the LOT. Fodor's
initial proposal is that what determines that the symbol for "water" in
Mentalese expresses the property H2O is that the occurrences
of that symbol are in certain causal relations with water. The intuitive
version of this causal theory is what Fodor calls the "Crude Causal
Theory". According to this theory, the occurrences of symbols express
the properties which are the causes of their occurrence. The term
"horse", for example, says of a horse that it is a horse. In order to do
this, it is necessary and sufficient that certain properties of an
occurrence of the symbol "horse" be in a law-like relation with certain
properties which determine that something is an occurrence of horse.
The main problem with this theory is that of erroneous
representations. There are two unavoidable problems with the idea that
"a symbol expresses a property if it is ... necessary that all and only
the presences of such a property cause the occurrences". The first is
that not all horses cause occurrences of horse. The second is that not only horses cause occurrences of horse. Sometimes the A(horses)
are caused by A (horses), but at other times—when, for example, because
of the distance or conditions of low visibility, one has confused a cow
for a horse—the A (horses) are caused by B (cows). In this case the symbol A
doesn't express just the property A, but the disjunction of properties A
or B. The crude causal theory is therefore incapable of distinguishing
the case in which the content of a symbol is disjunctive from the case
in which it isn't. This gives rise to what Fodor calls the "problem of
disjunction".
Fodor responds to this problem with what he defines as "a
slightly less crude causal theory". According to this approach, it is
necessary to break the symmetry at the base of the crude causal theory.
Fodor must find some criterion for distinguishing the occurrences of A
caused by As (true) from those caused by Bs (false). The point of
departure, according to Fodor, is that while the false cases are ontologically dependent on the true cases, the reverse is not true. There is an asymmetry of dependence, in other words, between the true contents (A= A) and the false ones (A=A
or B). The first can subsist independently of the second, but the
second can occur only because of the existence of the first:
From the point of view of semantics, errors must be accidents:
if in the extension of "horse" there are no cows, then it cannot be
required for the meaning of "horse" that cows be called horses. On the
other hand, if "horse" did not mean that which it means, and if it were
an error for horses, it would never be possible for a cow to be called
"horse". Putting the two things together, it can be seen that the
possibility of falsely saying "this is a horse" presupposes the
existence of a semantic basis for saying it truly, but not vice versa.
If we put this in terms of the crude causal theory, the fact that cows
cause one to say "horse" depends on the fact that horses cause one to
say "horse"; but the fact that horses cause one to say "horse" does not depend on the fact that cows cause one to say "horse"...
Functionalism
During the 1960s, philosophers such as Donald Davidson, Hilary Putnam, and Fodor tried to resolve the puzzle of developing a way to preserve the explanatory efficacy of mental causation and folk psychology while adhering to a materialist
vision of the world which did not violate the "generality of physics".
Their proposal was, first of all, to reject the then-dominant theories
in philosophy of mind: behaviorism and the type identity theory. The problem with logical behaviorism was that it failed to account for causation between
mental states and such causation seems to be essential to psychological
explanation, especially if one considers that behavior is not an effect
of a single mental event/cause but is rather the effect of a chain of
mental events/causes. The type-identity theory, on the other hand,
failed to explain the fact that radically different physical systems can
find themselves in the identical mental state. Besides being deeply
anthropocentric (why should humans be the only thinking organisms in the
universe?), the identity-type theory also failed to deal with
accumulating evidence in the neurosciences that every single human brain
is different from all the others. Hence, the impossibility of referring
to common mental states in different physical systems manifests itself
not only between different species but also between organisms of the
same species.
An
illustration of multiple realizability. M stands for mental and P stand
for physical. The diagram shows that more than one P can instantiate
one M, but not vice versa. Causal relations between states are represented by the arrows (M1 goes to M2, etc.).
One can solve these problems, according to Fodor, with functionalism, a hypothesis which was designed to overcome the failings of both dualism and reductionism.
What is important is the function of a mental state regardless of the
physical substrate which implements it. The foundation for this view
lies in the principle of the multiple realizability
of the mental. Under this view, for example, I and a computer can both
instantiate ("realize") the same functional state though we are made of
completely different material stuff (see graphic at right). On this
basis functionalism can be classified as a form of token materialism.
Evolution
Fodor and the biolinguistMassimo Piattelli-Palmarini co-authored the book What Darwin Got Wrong (2010). In the same, the authors argue that much neo-Darwinian literature is "distressingly uncritical" and that Charles Darwin's
theory of evolution "overestimates the contribution the environment
makes in shaping the phenotype of a species and correspondingly
underestimates the effects of endogenous variables". Evolutionary biologist Jerry Coyne describes this book as "a profoundly misguided critique of natural selection" and "as biologically uninformed as it is strident". Moral philosopher and anti-scientism author Mary Midgley praises What Darwin Got Wrong as "an overdue and valuable onslaught on neo-Darwinist simplicities".
Philosophers of diverse orientations have challenged many of Fodor's ideas.
Simon Blackburn
Simon Blackburn in Spreading the Word (1984) has accused the language of thought hypothesis of falling prey to an infinite regress.
If a person understands a word like "dog" through a mental
representation which indicates that the word denotes dogs, then a
regress takes place. Fodor replies that the language of thought does not involve denoting things. On this view, the process of reasoning works directly to give a result but does not allow the person to examine how it works.
Daniel Dennett
In 1981, Daniel Dennett
formulated another argument against the LOT. Dennett suggested that it
would seem, on the basis of the evidence of our behavior toward
computers but also with regard to some of our own unconscious behavior,
that explicit representation is not necessary for the explanation of
propositional attitudes. During a game of chess with a computer program,
we often attribute such attitudes to the computer, saying such things
as "It thinks that the queen should be moved to the left." We attribute
propositional attitudes to the computer and this helps us to explain and
predict its behavior in various contexts. Yet no one would suggest that
the computer is actually thinking or believing somewhere inside its circuits the equivalent of the propositional attitude "I believe I can kick this guy's butt" in Mentalese.
The same is obviously true, suggests Dennett, of many of our everyday
automatic behaviors such as "desiring to breathe clear air" in a stuffy
environment.
Kent Bach
Linguists and philosophers of language such as Kent Bach have criticized Fodor's self-proclaimed "extreme" conceptnativism. Bach takes Fodor to task for his criticisms of lexical semantics and polysemy.
Fodor claims that there is no lexical structure to such verbs as
"keep", "get", "make" and "put". He suggests that, alternatively, "keep"
simply expresses the concept KEEP (Fodor capitalizes concepts to
distinguish them from properties, names or other such entities). If
there is a straightforward one-to-one mapping between individual words
and concepts, "keep your clothes on", "keep your receipt" and "keep
washing your hands" will all share the same concept of KEEP under
Fodor's theory. This concept presumably locks on to the unique external
property of keeping. But, if this is true, then RETAIN must pick out a
different property in RETAIN YOUR RECEIPT, since one can't retain one's
clothes on or retain washing one's hands. Fodor's theory also has a
problem explaining how the concept FAST contributes, differently, to the contents of FAST CAR, FAST DRIVER, FAST TRACK, and FAST TIME. Whether or not the differing interpretations of "fast" in these
sentences are specified in the semantics of English, or are the result
of pragmatic inference, is a matter of debate. Fodor's own response to this kind of criticism is expressed bluntly in Concepts: "People sometimes used to say that exist
must be ambiguous because look at the difference between 'chairs exist'
and 'numbers exist'. A familiar reply goes: the difference between the
existence of chairs and the existence of numbers seems, on reflection,
strikingly like the difference between numbers and chairs. Since you
have the latter to explain the former, you don't also need 'exist' to be
polysemic."
Some critics find it difficult to accept Fodor's insistence that a
large, perhaps implausible, number of concepts are primitive and
undefinable. For example, Fodor considers such concepts as EFFECT,
ISLAND, TRAPEZOID, and WEEK to be all primitive, innate and unanalyzable
because they all fall into the category of what he calls "lexical
concepts" (those for which our language has a single word). Against this
view, Bach argues that the concept VIXEN is almost certainly composed
out of the concepts FEMALE and FOX, BACHELOR out of SINGLE and MALE, and
so on.
Fiona Cowie
In her 1999 book What's Within, Fiona Cowie argued against Fodor's innatist view, preferring a John Locke-style empiricism. Fodor replied at length in a 1999 article titled "Doing Without What's Within; Fiona Cowie's Critique of Nativism", stating that he was aiming at a position halfway between nativism and empiricism.
A major branch of linguistics since the second half of the 20th century, sociolinguistics is closely related to and can partly overlap with pragmatics, linguistic anthropology, and sociology of language, the latter focusing on the effect of language back on society. Sociolinguistics' historical interrelation with anthropology can be observed in studies of how language varieties differ between groups separated by social variables (e.g., ethnicity, religion, status, gender, level of education, age, etc.) or geographical barriers (a mountain range, a desert, a river, etc.). Such studies also examine how such differences in usage and in beliefs about usage produce and reflect social or socioeconomic classes.
As the usage of a language varies from place to place, language usage
also varies among social classes, and some sociolinguists study these sociolects.
Studies in the field of sociolinguistics use a variety of research methods including ethnography
and participant observation, analysis of audio or video recordings of
real life encounters or interviews with members of a population of
interest. Some sociolinguists assess the realization of social and linguistic variables in the resulting speech corpus. Other research methods in sociolinguistics include matched-guise tests
(in which listeners share their evaluations of linguistic features they
hear), dialect surveys, and analysis of preexisting corpora.
Sociolinguistics in history
Beginnings
The
social aspects of language were in the modern sense first studied by
Indian and Japanese linguists in the 1930s, and also by forerunners in
Denmark and Switzerland around the turn of the 20th century, but none received much attention in the West until much later. The study of the social motivation of language change, on the other hand, has its foundation in the wave model of the late 19th century. The first attested use of the term sociolinguistics was by Thomas Callan Hodson in the title of his 1939 article "Sociolinguistics in India" published in Man in India.
Dialectology is an old field, and in the early 20th century, dialectologists such as Hans Kurath and Raven I. McDavid Jr. initiated large scale surveys of dialect regions in the U.S.
Sociolinguistics
can be divided into subfields, which make use of different research
methods, and have different goals. Dialectologists survey people
through interviews, and compile maps. Ethnographers such as Dell Hymes and his students often live amongst the people they are studying. Conversation analysts such as Harvey Sacks and interactional sociolinguists such as John J. Gumperz
record audio or video of natural encounters, and then analyze the tapes
in detail. Sociolinguists tend to be aware of how the act of
interviewing might affect the answers given.
Some sociolinguists study language on a national level among
large populations to find out how language is used as a social
institution. William Labov, a Harvard and Columbia University graduate, is often
regarded as the founder of variationist sociolinguistics which focuses
on the quantitative analysis of variation and change within languages, making sociolinguistics a scientific discipline.
For example, a sociolinguistics-based translation
framework states that a linguistically appropriate translation cannot
be wholly sufficient to achieve the communicative effect of the source
language; the translation must also incorporate the social practices and
cultural norms of the target language. To reveal social practices and cultural norms beyond lexical and
syntactic levels, the framework includes empirical testing of the
translation using methods such as cognitive interviewing with a sample population.
A commonly studied source of variation is regional dialects. Dialectology
studies variations in language based primarily on geographic
distribution and their associated features. Sociolinguists concerned
with grammatical and phonological features that correspond to regional
areas are often called dialectologists.
Sociolinguistic interview
The sociolinguistic interview
is the foundational method of collecting data for sociolinguistic
studies, allowing the researcher to collect large amounts of speech from
speakers of the language or dialect being studied. The interview takes
the form of a long, loosely structured conversation between the
researcher and the interview subject; the researcher's primary goal is
to elicit the vernacular style of speech: the register associated with everyday casual conversation. This goal is complicated by the observer's paradox: the researcher is trying to elicit the style of speech that would be used if the interviewer were not present.
To that end, a variety of techniques may be used to reduce the
subject's attention to the formality and artificiality of the interview
setting. For example, the researcher may attempt to elicit narratives of
memorable events from the subject's life, such as fights or near-death
experiences; the subject's emotional involvement in telling the story is
thought to distract their attention from the formality of the context.
Some researchers interview multiple subjects together to allow them to
converse more casually with one other than they would with the
interviewer alone. The researcher may then study the effects of style-shifting
on language by comparing a subject's speech style in more vernacular
contexts, such as narratives of personal experience or conversation
between subjects, with the more careful style produced when the subject
is more attentive to the formal interview setting. The correlations of
demographic features such as age, gender, and ethnicity with speech
behavior may be studied by comparing the speech of different interview
subjects.
Fundamental concepts
While
the study of sociolinguistics is very broad, there are a few
fundamental concepts on which many sociolinguistic inquiries depend.
Speech community
is a concept in sociolinguistics that describes a distinct group of
people who use language in a unique and mutually accepted way among
themselves. This is sometimes referred to as a Sprechbund.
To be considered part of a speech community, one must have a communicative competence.
That is, the speaker has the ability to use language in a way that is
appropriate in the given situation. It is possible for a speaker to be
communicatively competent in more than one language.
Demographic characteristics such as areas or locations have
helped to create speech community boundaries in speech community
concept. Those characteristics can assist exact descriptions of specific
groups' communication patterns.
Speech communities can be members of a profession with a specialized jargon, distinct social groups like high school students or hip hop fans, or even tight-knit groups like families and friends. Members of speech communities will often develop slang
or specialized jargon to serve the group's special purposes and
priorities. This is evident in the use of lingo within sports teams.
Community of Practice
allows for sociolinguistics to examine the relationship between
socialization, competence, and identity. Since identity is a very
complex structure, studying language socialization is a means to examine
the micro-interactional level of practical activity (everyday
activities). The learning of a language is greatly influenced by
family, but it is supported by the larger local surroundings, such as
school, sports teams, or religion. Speech communities may exist within a
larger community of practice.
Crucial to sociolinguistic analysis is the concept of prestige;
certain speech habits are assigned a positive or a negative value,
which is then applied to the speaker. This can operate on many levels.
It can be realized on the level of the individual sound/phoneme, as
Labov discovered in investigating pronunciation of the post-vocalic /r/
in the Northeastern United States, or on the macro scale of language
choice, as is realized in the various diglossia
that exist throughout the world, with the one between Swiss German and
High German being perhaps most well known. An important implication of
the sociolinguistic theory is that speakers 'choose' a variety when
making a speech act, whether consciously or subconsciously.
The terms acrolectal (high) and basilectal (low) are also used to
distinguish between a more standard dialect and a dialect of less
prestige.
It is generally assumed that non-standard language is
low-prestige language. However, in certain groups, such as traditional
working-class neighborhoods, standard language may be considered
undesirable in many contexts because the working-class dialect is
generally considered a powerful in-group marker. Historically, humans
tend to favor those who look and sound like them, and the use of
nonstandard varieties (even exaggeratedly so) expresses neighborhood
pride and group and class solidarity. The desirable social value
associated with the use of non-standard language is known as covert prestige.
There will thus be a considerable difference in use of non-standard
varieties when going to the pub or having a neighborhood barbecue
compared to going to the bank. One is a relaxed setting, likely with
familiar people, and the other has a business aspect to it in which one
feels the need to be more professional.
Social network
Understanding language in society means that one also has to understand the social networks
in which language is embedded. A social network is another way of
describing a particular speech community in terms of relations between
individual members in a community. A network could be loose or tight depending on how members interact with each other. For instance, an office or factory may be considered a tight community
because all members interact with each other. A large course with 100+
students would be a looser community because students may only interact
with the instructor and maybe 1–2 other students. A multiplex community is one in which members have multiple relationships with each other. For instance, in some neighborhoods, members may live on the same street, work for the same employer and even intermarry.
The looseness or tightness of a social network may affect speech
patterns adopted by a speaker. For instance, Sylvie Dubois and Barbara
Horvath found that speakers in one Cajun Louisiana community were more
likely to pronounce English "th" [θ] as [t] (or [ð] as [d]) if they
participated in a relatively dense social network (i.e. had strong local
ties and interacted with many other speakers in the community), and
less likely if their networks were looser (i.e. fewer local ties).
A social network may apply to the macro level of a country or a
city, but also to the interpersonal level of neighborhoods or a single
family. Recently, social networks have been formed by the Internet
through online chat rooms, Facebook groups, organizations, and online
dating services.
Sociolinguistics as a field distinct from dialectology
was pioneered through the study of language variation in urban areas.
Whereas dialectology studies the geographic distribution of language
variation, sociolinguistics focuses on other sources of variation, among
them class. Class and occupation are among the most important
linguistic markers found in society. One of the fundamental findings of
sociolinguistics, which has been hard to disprove, is that class and
language variety are related. Members of the working class tend to speak
less of what is deemed standard language,
while the lower, middle, and upper middle class will, in turn, speak
closer to the standard. However, the upper class, even members of the
upper middle class, may often speak 'less' standard than the middle
class. This is because not only class but class aspirations, are
important. One may speak differently or cover up an undesirable accent
to appear to have a different social status and fit in better with
either those around them, or how they wish to be perceived.
Class aspiration
Studies,
such as those by William Labov in the 1960s, have shown that social
aspirations influence speech patterns. This is also true of class
aspirations. In the process of wishing to be associated with a certain
class (usually the upper class and upper middle class) people who are
moving in that direction socio-economically may adjust their speech
patterns to sound like them. However, not being native upper-class
speakers, they often hypercorrect,
which involves overcorrecting their speech to the point of introducing
new errors. The same is true for individuals moving down in
socio-economic status.
In any contact situation, there is a power dynamic, be it a
teacher-student or employee-customer situation. This power dynamic
results in a hierarchical differentiation between languages.
Non-standard dialect (associated with lower classes)
Standard dialect (associated with higher classes)
It looks like it ain't gonna rain today.
It looks as if it isn't going to rain today.
You give it to me yesterday.
You gave it to me yesterday.
Y'gotta do it the right way.
You have to do it the right way.
Social language codes
Basil Bernstein, a well-known British sociolinguist, devised in his book, Elaborated and restricted codes: their social origins and some consequences,
a method for categorizing language codes according to variable emphases
on verbal and extraverbal communication. He claimed that factors like
family orientation, social control, verbal feedback, and possibly social
class contributed to the development of the two codes: elaborated and
restricted.
Restricted code
According
to Basil Bernstein, the restricted code exemplified the predominance of
extraverbal communication, with an emphasis on interpersonal connection
over individual expression. His theory places the code within
environments that operate according to established social structures
that predetermine the roles of their members in which the commonality of
interests and intents from a shared local identity creates a
predictability of discrete intent and therefore a simplification of
verbal utterances. Such environments may include military, religious,
and legal atmospheres; criminal and prison subcultures; long-term
married relationships; and friendships between children.
The strong bonds between speakers often renders explicit verbal
communication unnecessary and individual expression irrelevant. However,
simplification is not a sign of a lack of intelligence or complexity
within the code; rather, communication is performed more through
extraverbal means (facial expression, touch, etc.) in order to affirm
the speakers' bond. Bernstein notes the example of a young man asking a
stranger to dance since there is an established manner of asking, yet
communication is performed through physical graces and the exchange of
glances.
As such, implied meaning plays a greater role in this code than
in the elaborated code. Restricted code also operates to unify speakers
and foster solidarity.
Elaborated code
Basil
Bernstein defined 'elaborated code' according to its emphasis on verbal
communication over extraverbal. This code is typical in environments
where a variety of social roles are available to the individual, to be
chosen based upon disposition and temperament. Most of the time,
speakers of elaborated code use a broader lexicon
and demonstrate less syntactic predictability than speakers of
restricted code. The lack of predetermined structure and solidarity
requires explicit verbal communication of discrete intent by the
individual to achieve educational and career success.
Bernstein notes with caution the association of the code with
upper classes (while restricted code is associated with lower classes)
since the abundance of available resources allows persons to choose
their social roles. He warns, however, that studies associating the
codes with separate social classes used small samples and were subject
to significant variation.
He also asserts that elaborated code originates from differences
in social context, rather than intellectual advantages. As such,
elaborated code differs from restricted code according to the
context-based emphasis on individual advancement over assertion of
social/community ties.
The codes and child development
Bernstein
explains language development according to the two codes in light of
their fundamentally different values. For instance, a child exposed
solely to restricted code learns extraverbal communication over verbal,
and therefore may have a less extensive vocabulary than a child raised
with exposure to both codes. While there is no inherent lack of value to
restricted code, a child without exposure to elaborated code may
encounter difficulties upon entering formal education, in which
standard, clear verbal communication and comprehension is necessary for
learning and effective interaction both with instructors and other
students from differing backgrounds. As such, it may be beneficial for
children who have been exposed solely to restricted code to enter
pre-school training in elaborated code in order to acquire a manner of
speaking that is considered appropriate and widely comprehensible within
the education environment.
Additionally, Bernstein notes several studies in language
development according to social class. In 1963, the Committee for Higher
Education conducted a study on verbal IQ that showed a deterioration in
individuals from lower working classes ages 8–11 and 11–15 years in
comparison to those from middle classes (having been exposed to both
restricted and elaborated codes). Additionally, studies by Bernstein, Venables, and Ravenette, as well as a 1958 Education Council report, show a relative lack of success on verbal tasks in comparison to
extraverbal in children from lower working classes (having been exposed
solely to restricted code).
Contradictions
The idea of these social language codes from Bernstein contrast with famous linguist Noam Chomsky's ideas. Chomsky, deemed the "father of modern linguistics", argues that there is a universal grammar,
meaning that humans are born with an innate capacity for linguistic
skills like sentence-building. This theory has been criticized by
several scholars of linguistic backgrounds because of the lack of proven
evolutionary feasibility and the fact that different languages do not
have universal characteristics.
The study of language variation is concerned with social constraints determining language in its contextual environment.
The variations will determine some of the aspects of language like the
sound, grammar, and tone in which people speak, and even non-verbal
cues. Code-switching
is the term given to the use of different varieties of language
depending on the social situation. This is commonly used among the
African-American population in the United States. There are several
different types of age-based variation one may see within a population
as well such as age range, age-graded variation, and indications of
linguistic change in progress. The use of slang can be a variation based
on age. Younger people are more likely to recognize and use today's
slang while older generations may not recognize new slang, but might use
slang from when they were younger.
Variation may also be associated with gender, as men and women,
on average, tend to use slightly different language styles. These
differences are typically quantitative rather than qualitative. In other
words, while women may use certain speaking styles more frequently than
men, the distinction is comparable to height differences between the
sexes—on average, men are taller than women, yet some women are taller
than some men. Similar variations in speech patterns include differences
in pitch, tone, speech fillers, interruptions, and the use of
euphemisms, etc.
These gender-based differences in communication extend beyond
face-to-face interactions and are also evident in digital spaces.
Despite the continuous evolution of social media platforms, cultural and
societal norms continue to shape online interactions. For instance, men
and women often adopt different non-verbal cues and roles in virtual
conversations. However, when it comes to fundamental aspects of
communication—such as spoken language, active listening, providing
feedback, understanding context, selecting communication methods, and
managing conflicts—their approaches tend to be more similar than
different.
Beyond these stylistic differences, research suggests that
gendered language patterns are also influenced by social expectations
and power dynamics. Women, for instance, are more likely to use hedging
expressions (e.g., "I think" or "perhaps") and tag questions ("isn't
it?") to soften their statements and promote conversational cooperation. Meanwhile, men tend to adopt more assertive and direct speech patterns,
reflecting broader societal norms that associate masculinity with
dominance and authority.
Variation in language can also come from ethnicity, economic status, level of education, etc.
Population
structure of African populations in a broad context. ADMIXTURE analysis
of 2,194 individuals from 81 populations for 16,420 SNPs reveals both
well-established and novel ancestry components in African populations.
The genetic history of Africa summarizes the genetic makeup and population history of African populations in Africa, composed of the overall genetic history, including the regional genetic histories of North Africa, West Africa, East Africa, Central Africa, and Southern Africa, as well as the recent origin of modern humans in Africa. The Sahara served as a trans-regional passageway and place of dwelling for people in Africa during various humid phasesand periods throughout the history of Africa. It also served as a biological barrier that restricted geneflow between
the northern and central parts of Africa since its desertification,
contributing to the diverse and distinct population structures on the
continent. Nonetheless, this did not stop contact between peoples north
and south of the Sahara at various points, especially in prehistoric
times when the climate conditions were warmer and wetter.
Overview
(A)
the origin of the 46 African ethnic groups used in the analysis; ethnic
groups from similar regions are given the same colour, but different
shapes. (B) PCA shows that the first major axis of variation in Africa
(PC1, y-axis) splits southern groups from the rest of Africa, each
symbol represents an individual; PC2 (x-axis) reflects ethno-linguistic
differences, with Niger-Congo and Nilo-Saharan speakers split from
Afroasiatic speakers. (C) The third principal component (PC3, x-axis)
represents geographical separation of Niger-Congo speakers, forming a
cline from west to east Africans.
The peoples of Africa
are characterized by regional genetic substructure and heterogeneity,
depending on the respective ethno-linguistic identity, and, in part,
explainable by the "multiregional evolution" of modern human lineages in
various multiple regions of the African continent, as well as later
admixture events, including back-migrations from Eurasia, of both highly
differentiated West and East Eurasian components.
Africans' genetic ancestry is largely partitioned by geography and language family,
with populations belonging to the same ethno-linguistic groupings
showing high genetic homogeneity and coherence. Gene flow, consistent
with both short- and long-range migration events followed by extensive
admixture and bottleneck events, have influenced the regional genetic makeup and demographic structure of Africans. The historical Bantu expansion had lasting impacts on the modern demographic make up of Africa, resulting in a greater genetic and linguistic homogenization. Genetic, archeologic, and linguistic studies added extra insight into
this movement: "Our results reveal a genetic continuum of Niger–Congo
speaker populations across the continent and extend our current
understanding of the routes, timing and extent of the Bantu migration."
Overall, different African populations display genetic diversity
and substructure, but can be clustered in distinct but partially
overlapping groupings:
Khoisan or 'South African hunter-gatherers' from Southern Africa represented by the Khoisan peoples;
they are associated with the deepest divergence (c. 270,000 years ago)
of human genetic diversity, forming a distinct cluster of their own.
They subsequently diverged into a Northern and Southern subgroup, c.
30,000 years ago.
'Central African hunter-gatherers' or 'Rain forest hunter-gatherers' (Pygmies) of Central Africa, represented by the Biaka and Mbuti;
associated with another deep divergence (c. 220,000 years ago). They
subsequently diverged into an Eastern and Western subgroup, c. 20,000
years ago.
"Ancestral Eurasians" represent the ancestral population of
modern Eurasians shortly before the Out-of-Africa expansion; they are
inferred to have diverged from other African populations, most likely
somewhere in Northeast Africa, c. 70,000 years ago.
The various Afroasiatic-speakers from Northern Africa and the Horn of Africa,
are suggested to have diverged from other African groups c. 50,000
years ago, but currently insufficient data and geneflow from other
groups complicate an accurate estimation of the divergence date. Afroasiatic-speaking populations also display variable amounts of West Asian (primarily Natufian-like, but also Neolithic Anatolian and Iranian)
admixtures from Eurasian backflow movements, with the remainder being
primarily from autochthonous African genetic clusters, associated with Nilotic-like ancestry. They also display affinity for the Paleolithic North African Taforalt specimens of the Iberomaurusian culture.
'Eastern African hunter-gatherers', represented by Hadza, Sandawe, Omotic-speakers,
and the ancient Mota specimen; their phylogenetic relationship to other
populations is not clear, but they display affinity to modern East and
West African populations, and harbor Khoesan-like geneflow along a
Northeast to Southwest cline, as well as later (West) Eurasian
admixtures, but at lower amounts than among Afroasiatic-speakers.
"Ancient East Africans" or "Ancestral West/East Africans" associated with the common ancestor of modern Niger-Congo and Nilo-Saharan-speakers originated around 28,000 years ago, likely in the Nile Valley
region. They subsequently diverged at c. 18,000 years ago into the
ancestors of West and West-Central African Niger-Congo and
Bantu-speakers, and into the East African Nilo-Saharan/Nilotic-speakers.
They represent the dominant and most widespreaded ancestry component of
modern Africa, and are associated with relative recent population
expansions linked to agriculture and pastoralist lifestyles. Genetic
data indicates affinity for older hunter-gatherer groups in East Africa,
but their exact relationship remains unclear. There is evidence for limited geneflow (9–13%) from a human ghost lineage,
referred to as 'West African foragers' with a deeper or equally deep
divergence time than 'Khoisan hunter-gatherers', into modern West
Africans.
Geographic
location of the samples analyzed in this study (A). PCA of the Khoe-San
individuals, Eurasians, West and East Africans before (unmasked, B) and
after (masked, C) applying the local ancestry pipeline (146,696
independent SNPs).
Although the validity of the Nilo-Saharan family remains controversial, the region between Chad, Sudan, and the Central African Republic is seen as a likely candidate for its homeland prior to its dispersal around 10,000–8,000 BCE.
The Southern African hunter-gatherers (Khoisan) are suggested to
represent the autochthonous hunter-gatherer population of southern
Africa, prior to the expansion of Bantu-speakers from Western/Central
Africa and East African pastoralists. Khoisan show evidence for
Bantu-related admixture, ranging from nearly ~0% to up to ~87.1%.
Human migration routes following Out-of-Africa.Most
modern Africans display a high level of genetic homogeneity, but
contributions from Eurasian populations are substantial, mostly
concentrated in the Northeastern part of Africa and Madagascar.
The "recent African origin of modern humans" proposes a "single origin" of Homo sapiens
within Africa. Recent genetic and archeologic data suggests that Homo
sapiens-subgroups originated in multiple regions of Africa, not confined
to a single sub-region of origin, with the last common ancestor of all
modern humans expanding from a single region absorbing or replacing
various deep lineages (described as archaic ghosts). The H. sapiens ancestral to proper Eurasians most likely left Northeastern Africa between 50,000 and 100,000 years ago. The "recent African origin" model proposes that all modern non-African populations descend from one or several waves of H. sapiens that left Africa 70,000–60,000 years ago.
According
to serial founder model, the earliest-branching non-African lineages
are expected to have expanded in the Middle East, after the
Out-of-Africa event (a), but have their deepest divergence in modern-day
East or Southeast Asia (b), suggesting either rapid diversification and
substructure within the early Eurasians, or replacement and loss of
deep lineages in Western Eurasia. Simplified Y tree is shown as
reference for colours.
According to Durvasula et al. (2020), there are indications that 2%
to 19% (≃6.6 to 7.0%) of the DNA of West African populations may have
come from an unknown archaic hominin which split from the ancestor of
humans and Neanderthals between 360 kya to 1.02 mya. However, Durvasula
et al. (2020) also suggests that at least part of this archaic admixture
is also present in Eurasians/non-Africans, and that the admixture event
or events range from 0 to 124 ka B.P, which includes the period before
the Out-of-Africa migration and prior to the African/Eurasian split
(thus affecting in part the common ancestors of both Africans and
Eurasians/non-Africans).Chen et al. (2020) found that Africans have higher Neanderthal
ancestry than previously thought. 2,504 African samples from all over
Africa were analyzed and tested on Neanderthal ancestry. All African
samples showed evidence for minor Neanderthal ancestry, but always at
lower levels than observed in Eurasians.
Pre-Neolithic and Neolithic migration events in Africa.A visual summary of the main admixture movements into and within Africa.
Significant Eurasian admixture is found in Northern Africa, and among specific ethnic groups of the Horn of Africa, Northern Sudan, the Sahel region, as well as among the Malagasy people of Madagascar. Various genome studies found evidence for multiple prehistoric back-migrations from various Eurasian populations and subsequent admixture with native groups. West Eurasian-associated geneflow arrived to Northern Africa during the
Paleolithic (30,000 to 15,000 years ago), followed by other
pre-Neolithic and Neolithic migration events. Genetic data on the Taforalt
samples "demonstrated that Northern Africa received significant amounts
of gene-flow from Eurasia predating the Holocene and development of
farming practices". Medieval geneflow events, such as the Arab expansion
also left traces in various African populations. Pickrell et al. (2014) indicated that Western Eurasian ancestry eventually arrived through Northeast Africa (particularly the Horn of Africa) to Southeast Africa and Southern Africa.
Ramsay et al. (2018) also found evidence for significant Western
Eurasian admixture in various parts of Africa, from both ancient and
more recent migrations, being highest among populations from Northern Africa, and some groups of the Horn of Africa:
In addition to the intrinsic diversity within the
continent due to population structure and isolation, migration of
Eurasian populations into Africa has emerged as a critical contributor
to the genetic diversity. These migrations involved the influx of
different Eurasian populations at different times and to different parts
of Africa. Comprehensive characterization of the details of these
migrations through genetic studies on existing populations could help to
explain the strong genetic differences between some geographically
neighbouring populations.
This distinctive Eurasian admixture appears to have occurred over
at least three time periods with ancient admixture in central west
Africa (e.g., Yoruba from Nigeria) occurring between ~7.5 and 10.5 kya,
older admixture in east Africa (e.g., Ethiopia) occurring between ~2.4
and 3.2 kya and more recent admixture between ~0.15 and 1.5 kya in some
east African (e.g., Kenyan) populations.
Subsequent studies based on LD decay and haplotype sharing in an
extensive set of African and Eurasian populations confirmed the presence
of Eurasian signatures in west, east and southern Africans. In the
west, in addition to Niger-Congo speakers from The Gambia and Mali, the
Mossi from Burkina Faso showed the oldest Eurasian admixture event ~7
kya. In the east, these analyses inferred Eurasian admixture within the
last 4000 years in Kenya.
Ancestral
components of various human populations using a four-way Admixture
model. European and Middle Eastern (Western Eurasian) ancestry is found
in many African groups.
There is no definitive agreement on when or where the original homeland of the Afroasiatic language family existed. Some have suggested that they were spread by people with largely West-Eurasian ancestry during the Neolithic Revolution, towards Northern Africa and the Horn of Africa, outgoing from the Middle East, specifically from the Levant. Others argue that the first speakers of Proto-Afroasiatic
were based in Northeast Africa because that region includes the
majority of the diversity of the Afroasiatic language family and has
very diverse groups in close geographic proximity, which is sometimes
considered a telltale sign for a linguistic geographic origin. A subset of the Proto-Afroasiatic population would have migrated to the Levant during the late Paleolithic, merging with local West-Eurasians and resulting in a population which would later give rise to Natufian culture, associated with the early development of agriculture and early Afroasiatic languages, or specifically pre-proto-Semitic. In addition, Y-haplogroup sub-lineage E-M215
(also known as "E1b1b) and its derivative E-M35 are quite common among
Afroasiatic speakers, and southwestern Ethiopia is a plausible source of
these haplogroups. Under this African model, the linguistic group and carriers of this
lineage would have arisen and dispersed together from Northeast Africa
in the Mesolithic, plausibly having already developed subsistence patterns of pastoralism and intensive plant usage and collection.
The Near-Eastern agriculturalist hypothesis does not account for the domestication of plants endemic to the Horn of Africa such as teff, ensete, and Niger seed, nor does it account for the lack of evidence of intrusive agricultural populations or for the growing of wheat, barley, or sorghum in that region prior to 3000 B.C. According to historian and linguist Christopher Ehret,
the form of intensive plant collection practiced by the
Proto-Afroasiatic population in Northeast Africa may have been a
precursor to the other agricultural practices that would later
independently develop in the Fertile Crescent and the Horn of Africa.
Proposed migration routes of paternal lineage E.
Horn of Africa
While many studies conducted on Horn of Africa populations estimate a West-Eurasian admixture event around 3,000 years ago, Hodgson et al. (2014) found a distinct West-Eurasian ancestral
component among studied Afroasiatic-speaking groups in the Horn of
Africa (and to a lesser extent in North Africa and West Asia), most prevalent among the ethnic Somali. This ancestral component dubbed "Ethio-Somali" is most closely related to the "Maghrebi" (peaking in Tunisians) component and is believed to have diverged from other non-African
ancestries around 23,000 years ago, and migrated back to Africa prior
to developing agriculture (12–23 ka) from the Near East. This population
would have crossed via the Sinai Peninsula and then split into two,
with one branch continuing west across North Africa and the other
heading south into the Horn of Africa. The authors propose that the
"Ethio-Somali" component may have been a substantial ancestral component
of the Proto-Afroasiatic-speaking population. Later migration from
Arabia into the HOA beginning around 3 ka would explain the origin of
the Ethiosemitic languages at this time. An mtDNA
analysis by Gandini et al. (2016) has produced additional evidence in
support of a pre-agricultural back-migration from West-Eurasia into the Horn of Africa with an estimated date of arrival into the Horn of Africa in the early Holocene, possibly as a result of obsidian exchange networks across the Red Sea. Hodgson et al. also confirmed the existence of an ancestral component
indigenous to the Horn of Africa - "Ethiopic" or "Omotic" (Pagani et
al.) - which is most prevalent among speakers of the Omotic branch of Afroasiatic in southwestern Ethiopia. This lineage is associated with that of a 4,500 year-old fossil (Mota)
found in a cave in southwestern Ethiopia, which has high genetic
affinity to modern Ethiopian groups, especially the endogamous blacksmith caste of the Omotic Aari people.
Like Mota, Aari blacksmiths do not show evidence for admixture with
West-Eurasians, demonstrating a degree of population continuity in this
region for at least 4,500 years. In a comparative analysis of Mota's
genome referencing modern populations, Gallego et al. (2016) concluded
that the divergence of Omotic from other Afroasiatic languages may have
resulted from the relative isolation of its speakers from external
groups.
In an analysis of 68 Ethiopian ethnic groups, Lopez et al. (2021)
revealed that several groups belonging to the three AA classifications
of Cushitic, Omotic and Semitic show high genetic similarity to each
other on average. Furthermore, the Nilo-Saharan speakers in the
southwest shared more recent ancestry with Bantu and Nilotics, in
contrast Afro-Asiatic speakers in the northeast shared more recent
ancestry with Egyptians and other West Eurasians. The data also supported widespread recent intermixing among various ethnic groups.
Madagascar
Austronesian expansion, outgoing from Taiwan and the northern Philippines.
Specific East Asian-related ancestry is found among the Malagasy speakers of Madagascar at a medium frequency. The presence of this East Asian-related ancestry is mostly linked to the Austronesian peoples expansion from Southeast Asia. The peoples of Borneo
were identified to resemble the East Asian voyagers, who arrived on
Madagascar. East Asian ancestry among Malagasy people was estimated at a
mean average of 33%, but as high as ~75% among some Highlander groups
and upper caste groups.
Northern Africa
Dobon
et al. (2015) identified an autosomal ancestral component that is
commonly found among modern Afroasiatic-speaking populations (as well as
Nubians) in Northeast Africa. This Coptic component peaks among Copts in Sudan,
which is differentiated by its lack of Arab influence, but shares
common ancestry with the North African/Middle Eastern populations. It
appears alongside a component that defines Nilo-Saharan speakers of southwestern Sudan and South Sudan. Arauna et al. (2017), analyzing existing genetic data obtained from Northern African populations, such as Berbers, described them as a mosaic of North African (Taforalt), Middle Eastern, European (Early European Farmers), and Sub-Saharan African-related ancestries.
Chen et al. (2020) analyzed 2,504 African samples from all over
Africa, and found archaic Neanderthal ancestry, among all tested African
samples at low frequency. They also identified a European-related
(West-Eurasian) ancestry segment, which seems to largely correspond with
the detected Neanderthal ancestry components. European-related
admixture among Africans was estimated to be between ~0% to up to ~30%,
with a peak among Northern Africans. According to Chen et al. (2020), "These data are consistent with the
hypothesis that back-migration contributed to the signal of Neanderthal
ancestry in Africans. Furthermore, the data indicates that this
back-migration came after the split of Europeans and East Asians, from a
population related to the European lineage."
There is a minor geneflow from North Africa in parts of Southern Europe, this is supported by the presence of an African-specific mitochondrial haplogroup among one of four 4,000 year old samples. Multiple studies found also evidence for geneflow of African ancestry
towards Eurasia, specifically Europe and the Middle East. The analysis
of 40 different West-Eurasian populations found African admixture at a
frequency of 0% to up to ~15%.
Western Africa
Hollfelder et al. (2021) concluded that West African Yoruba people,
which were previously used as "unadmixed reference population" for
indigenous Africans, harbor minor levels of Neanderthal ancestry, which
can be largely associated with back-migration of an "Ancestral
European-like" source population.
A genome-wide study of a Fulani community from Burkina Faso
inferred two major admixture events in this group, dating to ~1800 ya,
and 300 ya. The first admixture event took place between the West
African ancestors of the Fula and ancestral North African nomadic
groups. The second admixture event, relatively recent, inferred a source
from Southwestern Europe, or suggests either an additional gene flow
between the Fulani and Northern African groups, who carry admixture
proportions from Europeans. Sahelian populations like the Toubou also showed admixture coming from Eurasians.
Southern Africa
Low
levels of West Eurasian ancestry (European or Middle Eastern) are found
in Khoe–Kwadi Khoesan-speakers. It could have been acquired indirectly
by admixture with migrating pastoralists from East Africa. This
hypothesis of gene flow from eastern to southern Africa is further
supported by other genetic and archaeological data documenting the
spread of pastoralism from East to South Africa.
While Denisovan and Neanderthal ancestry in non-Africans outside of Africa are more certain, archaic human ancestry in Africans is less certain and is too early to be established with certainty.
Ancient DNA
Daniel
Shriner (2018), using modern populations as a reference, showed that
the Natufians carried 61.2% Arabian, 21.2% Northern African, 10.9%
Western Asian, and a small portion of Eastern African ancestry at 6.8%,
which is associated with the modern Omotic-speaking groups found in
southern Ethiopia.
Van de Loorsdrecht et al. (2018) found that of seven samples of Taforalts of Morocco, radiocarbon dated to between 15,100 cal BP and 13,900 cal BP, six were found to carry maternal haplogroup U6a, and one was found to carry maternal haplogroup M1b. All six males were found to carry paternal haplogroup E1b1b, and they harbored 63.5% Natufian-related ancestry and 36.5% Sub-Saharan African-related ancestry. The Sub-Saharan component is most strongly drawn out by modern West African groups such as the Yoruba and the Mende.
The samples also contain an additional affinity to South, Central, and
East African outgroups that cannot be explained by any known ancient or
modern populations. When projected onto a principal component analysis
graph of African and west Eurasian populations, the Taforalt
individuals form a distinct cluster in an intermediate position between
modern North Africans (e.g., Berbers, Mozabites, Saharawis) and East Africans (e.g., Afars, Oromos, Somalis). Jeong (2020), when comparing the Taforalt people of the Iberomaurusian
culture to modern populations, found that the Taforalt's Sub-Saharan
African genetic component may be best represented by modern West
Africans (e.g., Yoruba).
Amid the Holocene, including the Holocene Climate Optimum
in 8000 BP, Africans bearing haplogroup L2 spread within West Africa
and Africans bearing haplogroup L3 spread within East Africa. As the largest migration since the Out of Africa migration,
migration from Sub-Saharan Africa toward the North Africa occurred, by
West Africans, Central Africans, and East Africans, resulting in
migrations into Europe and Asia; consequently, Sub-Saharan African mitochondrial DNA was introduced into Europe and Asia. During the early period of the Holocene, 50% of Sub-Saharan African mitochondrial DNA was introduced into North Africa by West Africans and the other 50% was introduced by East Africans. During the modern period, a greater number of West Africans introduced
Sub-Saharan African mitochondrial DNA into North Africa than East
Africans.
Mitochondrial haplogroups L3, M, and N are found among Sudanese peoples (e.g., Beja, Nilotics, Nuba, Nubians),
who have no known interaction (e.g., history of migration/admixture)
with Europeans or Asians; rather than having developed in a
post-Out-of-Africa migration context, mitochondrial macrohaplogroup
L3/M/N and its subsequent development into distinct mitochondrial
haplogroups (e.g., Haplogroup L3, Haplogroup M, Haplogroup N) may have occurred in East Africa at a time that considerably predates the Out-of-Africa migration event of 50,000 BP.
Neolithicagriculturalists, who may have resided in Northeast Africa and the Near East, may have been the source population for lactase persistence variants, including –13910*T, and may have been subsequently supplanted by later migrations of peoples. The Sub-SaharanWest African Fulani, the North AfricanTuareg, and European agriculturalists, who are descendants of these Neolithic agriculturalists, share the lactase persistence variant –13910*T. While shared by Fulani and Tuareg herders, compared to the Tuareg
variant, the Fulani variant of –13910*T has undergone a longer period of
haplotype differentiation. The Fulani lactase persistence variant –13910*T may have spread, along with cattle pastoralism,
between 9686 BP and 7534 BP, possibly around 8500 BP; corroborating
this timeframe for the Fulani, by at least 7500 BP, there is evidence of
herders engaging in the act of milking in the Central Sahara.
Archaic traits found in human fossils of West Africa (e.g., Iho Eleru fossils, which dates to 13,000 BP) and Central Africa (e.g., Ishango
fossils, which dates between 25,000 BP and 20,000 BP) may have
developed as a result of admixture between archaic humans and modern
humans or may be evidence of late-persisting early modern humans. While Denisovan and Neanderthal ancestry in non-Africans outside of Africa are more certain, archaic human ancestry in Africans is less certain and is too early to be established with certainty.
Ancient DNA
As of 2017, human ancient DNA has not been found in the region of West Africa. As of 2020, human ancient DNA has not been forthcoming in the region of West Africa.
As a result of haplogroup D0, a basal branch of haplogroup DE, being found in three Nigerian men, it may be the case that haplogroup DE, as well as its sublineages D0 and E, originated in Africa.
During the early period of the Holocene, in 9000 BP, Khoisan-related peoples admixed with the ancestors of the Igbo people, possibly in the western Sahara.
Fan et al. (2019) found that the Fulani people show genetic affinity to isolated Afroasiatic-speaking groups in Eastern Africa, specifically Omotic-speakers such as the Aari people.
While the Fulani have nearly exclusive indigenous African ancestry
(defined by West and East African ancestry), they also show traces of
West-Eurasian-like admixture, supporting an ancestral homeland somewhere
in North or Eastern Africa, and westwards expansion during the
Neolithic, possibly caused by the arrival and expansion of
West-Eurasian-related groups. Fan et al. (2023) found that the Fulani, who have 50% Amhara-related and 50% Tikari-related ancestry as well as occupy regions such as West Africa, Central Africa, and the Sudan as nomadic herders, may have initially been Afroasiatic speakers that subsequently underwent language replacement and became Niger-Congo speakers.
Amid the Green Sahara, the mutation for sickle cell originated in the Sahara or in the northwest forest region of western Central Africa (e.g., Cameroon) by at least 7,300 years ago, though possibly as early as 22,000 years ago. The ancestral sickle cell haplotype to modern haplotypes (e.g., Cameroon/Central African Republic and Benin/Senegal haplotypes) may have first arose in the ancestors of modern West Africans, bearing haplogroups E1b1a1-L485 and E1b1a1-U175 or their ancestral haplogroup E1b1a1-M4732. West Africans (e.g., Yoruba and Esan of Nigeria), bearing the Benin sickle cell haplotype, may have migrated through the northeastern region of Africa into the western region of Arabia. West Africans (e.g., Mende of Sierra Leone), bearing the Senegal sickle cell haplotype, may have migrated into Mauritania (77% modern rate of occurrence) and Senegal (100%); they may also have migrated across the Sahara, into North Africa, and from North Africa, into Southern Europe, Turkey, and a region near northern Iraq and southern Turkey. Some may have migrated into and introduced the Senegal and Benin sickle cell haplotypes into Basra, Iraq, where both occur equally. West Africans, bearing the Benin sickle cell haplotype, may have migrated into the northern region of Iraq (69.5%), Jordan (80%), Lebanon (73%), Oman (52.1%), and Egypt (80.8%).
Archaic traits found in human fossils of West Africa (e.g., Iho Eleru fossils, which dates to 13,000 BP) and Central Africa (e.g., Ishango
fossils, which dates between 25,000 BP and 20,000 BP) may have
developed as a result of admixture between archaic humans and modern
humans or may be evidence of late-persisting early modern humans. While Denisovan and Neanderthal ancestry in non-Africans outside of Africa are more certain, archaic human ancestry in Africans is less certain and is too early to be established with certainty.
Haplogroup R1b-V88 is thought to have originated in Europe and migrated into Africa with farmers or herders in the Neolithic period, c. 5500 BC. R1b-V88 is found at a high frequency among Chadic speaking peoples such as the Hausa, as well as in Kanembu, Fulani, and Toubou populations.
In 150,000 BP, Africans (e.g., Central Africans, East Africans) bearing haplogroup L1 diverged. Between 75,000 BP and 60,000 BP, Africans bearing haplogroup L3 emerged in East Africa and eventually migrated into and became present in modern West Africans, Central Africans, and non-Africans. Amid the Holocene, including the Holocene Climate Optimum
in 8000 BP, Africans bearing haplogroup L2 spread within West Africa
and Africans bearing haplogroup L3 spread within East Africa. As the largest migration since the Out of Africa migration,
migration from Sub-Saharan Africa toward the North Africa occurred, by
West Africans, Central Africans, and East Africans, resulting in
migrations into Europe and Asia; consequently, Sub-Saharan African mitochondrial DNA was introduced into Europe and Asia.
While Denisovan and Neanderthal ancestry in non-Africans outside of Africa are more certain, archaic human ancestry in Africans is less certain and is too early to be established with certainty.
Ancient DNA
Ethiopia
At Mota, in Ethiopia, an individual, estimated to date to the 5th millennium BP, carried haplogroups E1b1 and L3x2a. The individual of Mota is genetically related to groups residing near
the region of Mota, and in particular, are considerably genetically
related to the Aari people, especially the blacksmith caste of that group.
In 150,000 BP, Africans (e.g., Central Africans, East Africans) bearing haplogroup L1 diverged. In 130,000 BP, Africans bearing haplogroup L5 diverged in East Africa. Between 130,000 BP and 75,000 BP, behavioral modernity emerged among Southern Africans and long-term interactions between the regions of Southern Africa and Eastern Africa became established. Between 75,000 BP and 60,000 BP, Africans bearing haplogroup L3 emerged in East Africa and eventually migrated into and became present in modern West Africans, Central Africans, and non-Africans. Amid the Holocene, including the Holocene Climate Optimum
in 8000 BP, Africans bearing haplogroup L2 spread within West Africa
and Africans bearing haplogroup L3 spread within East Africa. As the largest migration since the Out of Africa migration,
migration from Sub-Saharan Africa toward the North Africa occurred, by
West Africans, Central Africans, and East Africans, resulting in
migrations into Europe and Asia; consequently, Sub-Saharan African mitochondrial DNA was introduced into Europe and Asia. During the early period of the Holocene, 50% of Sub-Saharan African mitochondrial DNA was introduced into North Africa by West Africans and the other 50% was introduced by East Africans. During the modern period, a greater number of West Africans introduced
Sub-Saharan African mitochondrial DNA into North Africa than East
Africans. Between 15,000 BP and 7000 BP, 86% of Sub-Saharan African mitochondrial DNA was introduced into Southwest Asia by East Africans, largely in the region of Arabia, which constitute 50% of Sub-Saharan African mitochondrial DNA in modern Southwest Asia. In the modern period, 68% of Sub-Saharan African mitochondrial DNA was
introduced by East Africans and 22% was introduced by West Africans,
which constitutes 50% of Sub-Saharan African mitochondrial DNA in modern
Southwest Asia.
While Denisovan and Neanderthal ancestry in non-Africans outside of Africa are more certain, archaic human ancestry in Africans is less certain and is too early to be established with certainty.
Ancient DNA
Three Later Stone Agehunter-gatherers carried ancient DNA similar to Khoisan-speaking hunter-gatherers. Prior to the Bantu migration into the region, as evidenced by ancient DNA from Botswana, East Africanherders migrated into Southern Africa. Out of four Iron Age Bantu agriculturalists of West African origin, two earlier agriculturalists carried ancient DNA similar to Tsonga and Venda peoples and the two later agriculturalists carried ancient DNA similar to Nguni people;
this indicates that there were various movements of peoples in the
overall Bantu migration, which resulted in increased interaction and
admixing between Bantu-speaking peoples and Khoisan-speaking peoples.
Distribution of Y-Chromosome Haplogroup A in Africa.Distribution of haplogroup B (M60) of the human Y chromosome in native populations.
Various Y chromosome studies show that the San carry some of the most divergent (oldest) human Y-chromosome haplogroups. These haplogroups are specific sub-groups of haplogroups A and B, the two earliest branches on the human Y-chromosome tree.
Mitochondrial DNA
In 200,000 BP, Africans (e.g., Khoisan of Southern Africa) bearing haplogroup L0 diverged from other Africans bearing haplogroup L1′6, which tend to be northward of Southern Africa. Between 130,000 BP and 75,000 BP, behavioral modernity emerged among Southern Africans and long-term interactions between the regions of Southern Africa and Eastern Africa became established.
Mitochondrial DNA studies also provide evidence that the San carry high frequencies of the earliest haplogroup
branches in the human mitochondrial DNA tree. This DNA is inherited
only from one's mother. The most divergent (oldest) mitochondrial
haplogroup, L0d, has been identified at its highest frequencies in the southern African San groups.
Autosomal DNA
Henn et al. (2011) found that the ǂKhomani San, as well as the Sandawe and Hadza peoples of Tanzania, were the most genetically diverse of any living humans studied. This high degree of genetic diversity hints at the origin of anatomically modern humans.
Medical DNA
Among the ancient DNA from three hunter-gatherers sharing genetic similarity with San people and four Iron Age agriculturalists, their SNPs indicated that they bore variants for resistance against sleeping sickness and Plasmodium vivax. In particular, two out of the four Iron Age agriculturalists bore
variants for resistance against sleeping sickness and three out of the
four Iron Age agriculturalists bore Duffy negative variants for resistance against malaria. In contrast to the Iron Age agriculturalists, from among the
San-related hunter-gatherers, a six-year-old boy may have died from schistosomiasis. In Botswana, a man, who dates to 1400 BP, may have also carried the Duffy negative variant for resistance against malaria.
Between 500,000 BP and 300,000 BP, anatomically modern humans may have emerged in Africa. As Africans (e.g., Y-Chromosomal Adam, Mitochondrial Eve) have migrated from their places of origin in Africa to other locations in Africa, and as the time of divergence for East African, Central African, and West African lineages are similar to the time of divergence for the Southern African lineage, there is insufficient evidence to identify a specific region for the origin of humans in Africa. In 100,000 BP, anatomically modern humans migrated from Africa into Eurasia. Subsequently, tens of thousands of years after, the ancestors of all
present-day Eurasians migrated from Africa into Eurasia and eventually
became admixed with Denisovans and Neanderthals.
Archaeological and fossil evidence provide support for the African origin of homo sapiens and behavioral modernity. Models reflecting a pan-African origin (multiple locations of origin within Africa) and evolution of modern humans have been developed. As the idea of "modern" has become increasingly problematized, research
has "begun to disentangle what is meant by "modern" genetic ancestry,
skeletal morphology, and behavior, recognizing these are unlikely to
form a single package."
In comparison to the non-African genome, the African genome features a ~25% greater number of polymorphisms, or
3 to 5 times as many, and genetic variants that are rare outside of Africa are found to occur at an abundant rate within Africa. Most of the genetic diversity found among non-Africans is found to be,
at large, a subset of genetic diversity found among Africans. The genomes of Africans commonly found to undergo adaptation are regulatory DNA, and many cases of adaptation found among Africans relate to diet, physiology, and evolutionary pressures from pathogens. Throughout Sub-Saharan Africa, genetic adaptation (e.g., rs334 mutation, Duffy blood group, increased rates of G6PD deficiency, sickle cell disease) to malaria has been found among Sub-Saharan Africans, which may have initially developed in 7300 BP. Throughout Africa, various genetic adaptations (e.g., apolipoprotein L1 (APOL1): G1 and G2 haplotype resistance to trypanosomiasis and increased risk of kidney disease; human leukocyte antigen (HLA) genes; major histocompatibility complex (MHC)) to HIV-1, smallpox, trypanosomiasis (African sleeping sickness), and tuberculosis has been found among Africans. Biomedicaltests for specific genetic variants (e.g., rs1799853 in the CYP2C9 gene), which have been approved by the U.S. Food and Drug Administration and are intended to indicate correct prescription of warfarin, has been found to be increasingly irrelevant to Africans as the variants are rare in Africa. As frequency rate factors into considering and deciding variantpathogenicity and generalizable polygenic scores,
modern clinical classifications of genetic variant pathogenicity are
found to be inadequate due to a lack of genetic diversity in biomedical
studies. Fan et al (2023) recently found ~5.3 million unique genetic variants in 180 African hunter-gatherer populations, and among existing classifications for variants
determined to likely be "pathogenic", ~29% (44/154) of these
"pathogenic" classified variants were found to occur frequently among
the African hunter-gatherers.
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