Stanford prison experiment

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Stanford_prison_experiment 

Plaque at the location of the Stanford prison experiment

The Stanford prison experiment (SPE) was a social psychology experiment that attempted to investigate the psychological effects of perceived power, focusing on the struggle between prisoners and prison officers. It was conducted at Stanford University on the days of August 15–21, 1971, by a research group led by psychology professor Philip Zimbardo using college students. In the study, volunteers were assigned to be either "guards" or "prisoners" by the flip of a coin, in a mock prison, with Zimbardo himself serving as the superintendent. Several "prisoners" left mid-experiment, and the whole experiment was abandoned after six days. Early reports on experimental results claimed that students quickly embraced their assigned roles, with some guards enforcing authoritarian measures and ultimately subjecting some prisoners to psychological torture, while many prisoners passively accepted psychological abuse and, by the officers' request, actively harassed other prisoners who tried to stop it. The experiment has been described in many introductory social psychology textbooks, although some have chosen to exclude it because its methodology is sometimes questioned.

The U.S. Office of Naval Research funded the experiment as an investigation into the causes of difficulties between guards and prisoners in the United States Navy and United States Marine Corps. Certain portions of it were filmed, and excerpts of footage are publicly available.

The experiment's findings have been called into question, and the experiment has been criticized for unscientific methodology. Although Zimbardo interpreted the experiment as having shown that the "prison guards" instinctively embraced sadistic and authoritarian behaviors, Zimbardo actually instructed the "guards" to exert psychological control over the "prisoners". Critics also noted that some of the participants behaved in a way that would help the study, so that, as one "guard" later put it, "the researchers would have something to work with," which is known as demand characteristics. Variants of the experiment have been performed by other researchers, but none of these attempts have replicated the results of the SPE.

Zimbardo's goals

The (archived) official website of the Stanford Prison Experiment describes the experiment goal as follows:

We wanted to see what the psychological effects were of becoming a prisoner or prison guard. To do this, we decided to set up a simulated prison and then carefully note the effects of this institution on the behavior of all those within its walls.

A 1997 article from the Stanford News Service described experiment goals in a more detailed way:

Zimbardo's primary reason for conducting the experiment was to focus on the power of roles, rules, symbols, group identity and situational validation of behavior that generally would repulse ordinary individuals. "I had been conducting research for some years on deindividuation, vandalism and dehumanization that illustrated the ease with which ordinary people could be led to engage in anti-social acts by putting them in situations where they felt anonymous, or they could perceive of others in ways that made them less than human, as enemies or objects," Zimbardo told the Toronto symposium in the summer of 1996.

Experimental method

Male participants were recruited and told they would participate in a two-week prison simulation. The team selected the 24 applicants whose test results predicted they would be the most psychologically stable and healthy. These participants were predominantly white and of the middle class. The group was intentionally selected to exclude those with criminal backgrounds, psychological impairments, or medical problems. They all agreed to participate in a 7- to 14-day period and received $15 per day (roughly equivalent to $95 in 2019).

The experiment was conducted in a 35-foot (10.5 m) sections of a basement of Jordan Hall (Stanford's psychology building). The prison had two fabricated walls, one at the entrance, and one at the cell wall to block observation. Each cell (6 × 9 feet, or 1.8 × 2.7 m), contained only a cot for the prisoners. Prisoners were confined 24 hours/day. In contrast, the guards lived in a very different environment, separated from the prisoners. They were given rest and relaxation areas, and other comforts.

Twelve of the twenty-four participants were assigned the role of prisoner (nine plus three potential substitutes), while the other twelve were assigned the role of guard (also nine plus three potential substitutes). Zimbardo took on the role of the superintendent and an undergraduate research assistant took on the role of the warden. Zimbardo designed the experiment in order to induce disorientation, depersonalization, and deindividuation in the participants.

The researchers held an orientation session for the guards the day before the experiment, during which guards were instructed not to harm the prisoners physically or withhold food or drink. In the footage of the study, Zimbardo can be seen talking to the guards: "You can create in the prisoners feelings of boredom, a sense of fear to some degree, you can create a notion of arbitrariness that their life is totally controlled by us, by the system, you, me, and they'll have no privacy ... We're going to take away their individuality in various ways. In general what all this leads to is a sense of powerlessness. That is, in this situation we'll have all the power and they'll have none."

The researchers provided the guards with wooden batons to establish their status, clothing similar to that of an actual prison guard (khaki shirt and pants from a local military surplus store), and mirrored sunglasses to prevent eye contact. Prisoners wore uncomfortable, ill-fitting smocks and stocking caps, as well as a chain around one ankle. Guards were instructed to call prisoners by their assigned numbers, sewn on their uniforms, instead of by name.

The prisoners were "arrested" at their homes and "charged" with armed robbery. The local Palo Alto police department assisted Zimbardo with the simulated arrests and conducted full booking procedures on the prisoners, which included fingerprinting and taking mug shots. The prisoners were transported to the mock prison from the police station, where they were strip searched and given their new identities.

The small mock prison cells were set up to hold three prisoners each. There was a small corridor for the prison yard, a closet for solitary confinement, and a bigger room across from the prisoners for the guards and warden. The prisoners were to stay in their cells and the yard all day and night until the end of the study. The guards worked in teams of three for eight-hour shifts. The guards were not required to stay on-site after their shift.

Guards had differing responses to their new roles. One, described by Stanford Magazine as "the most abusive guard" felt his aggressive behavior was helping experimenters to get what they wanted. Another who had joined the experiment hoping to be selected as a prisoner, instead recalls "I brought joints with me, and every day I wanted to give them to the prisoners. I looked at their faces and saw how they were getting dispirited and I felt sorry for them," "Warden" David Jaffe intervened to change this guard's behavior, encouraging him to "participate" more and become more "tough."

Results

After a relatively uneventful first day, on the second day the prisoners in Cell 1 blockaded their cell door with their beds and took off their stocking caps, refusing to come out or follow the guards' instructions. Guards from other shifts volunteered to work extra hours, to assist in subduing the revolt, and subsequently attacked the prisoners with fire extinguishers without being supervised by the research staff. Finding that handling nine cell mates with only three guards per shift was challenging, one of the guards suggested they use psychological tactics to control them. They set up a "privilege cell" in which prisoners who were not involved in the riot were treated with special rewards, such as higher quality meals. The "privileged" inmates chose not to eat the meal in commiseration with their fellow prisoners.

After only 35 hours, one prisoner began to act "crazy", as Zimbardo described: "#8612 then began to act crazy, to scream, to curse, to go into a rage that seemed out of control. It took quite a while before we became convinced that he was really suffering and that we had to release him." Guards forced the prisoners to repeat their assigned numbers to reinforce the idea that this was their new identity. Guards soon used these prisoner counts to harass the prisoners, using physical punishment such as protracted exercise for errors in the prisoner count. Sanitary conditions declined rapidly, exacerbated by the guards' refusal to allow some prisoners to urinate or defecate anywhere but in a bucket placed in their cell. As punishment, the guards would not let the prisoners empty the sanitation bucket. Mattresses were a valued item in the prison, so the guards would punish prisoners by removing their mattresses, leaving them to sleep on concrete. Some prisoners were forced to be naked as a method of degradation. Several guards became increasingly cruel as the experiment continued; experimenters reported that approximately one-third of the guards exhibited genuine sadistic tendencies. Most of the guards were upset when the experiment was halted after only six days.

Zimbardo mentions his own absorption in the experiment. On the fourth day, some of the guards stated they heard a rumor that the released prisoner was going to come back with his friends and free the remaining inmates. Zimbardo and the guards disassembled the prison and moved it onto a different floor of the building. Zimbardo himself waited in the basement, in case the released prisoner showed up, and planned to tell him that the experiment had been terminated. The released prisoner never returned, and the prison was rebuilt in the basement.

Zimbardo argued that the prisoners had internalized their roles, since some had stated they would accept "parole" even if it would mean forfeiting their pay, despite the fact that quitting would have achieved the same result without the delay involved in waiting for their parole requests to be granted or denied. Zimbardo argued they had no reason for continued participation in the experiment after having lost all monetary compensation, yet they did, because they had internalized the prisoner identity.

Prisoner No. 416, a newly admitted stand-by prisoner, expressed concern about the treatment of the other prisoners. The guards responded with more abuse. When he refused to eat his sausages, saying he was on a hunger strike, guards confined him to "solitary confinement", a dark closet: "the guards then instructed the other prisoners to repeatedly punch on the door while shouting at 416." The guards said he would be released from solitary confinement only if the prisoners gave up their blankets and slept on their bare mattresses, which all but one refused to do.

Zimbardo aborted the experiment early when Christina Maslach, a graduate student in psychology whom he was dating (and later married), objected to the conditions of the prison after she was introduced to the experiment to conduct interviews. Zimbardo noted that, of more than 50 people who had observed the experiment, Maslach was the only one who questioned its morality. After only six days of a planned two weeks duration, the experiment was discontinued.

Conclusions

On August 20, 1971, Zimbardo announced the end of the experiment to the participants.

According to Zimbardo's interpretation of the SPE, it demonstrated that the simulated-prison situation, rather than individual personality traits, caused the participants' behavior. Using this situational attribution, the results are compatible with those of the Milgram experiment, where random participants complied with orders to administer seemingly dangerous and potentially lethal electric shocks to a shill.

The experiment has also been used to illustrate cognitive dissonance theory and the power of authority.

Participants' behavior may have been shaped by knowing that they were watched (Hawthorne effect). Instead of being restrained by fear of an observer, guards may have behaved more aggressively when supervisors observing them did not step in to restrain them.

Zimbardo instructed the guards before the experiment to disrespect the prisoners in various ways. For example, they had to refer to prisoners by number rather than by name. This, according to Zimbardo, was intended to diminish the prisoners' individuality. With no control, prisoners learned they had little effect on what happened to them, ultimately causing them to stop responding, and give up. Quick to realize that the guards were the highest in the hierarchy, prisoners began to accept their roles as less important human beings.

One positive result of the study is that it has altered the way US prisons are run. For example, juveniles accused of federal crimes are no longer housed before trial with adult prisoners, due to the risk of violence against them.

Shortly after the study was completed, there were bloody revolts at both the San Quentin and Attica prison facilities, and Zimbardo reported his findings on the experiment to the U.S. House Committee on the Judiciary.

Criticism and response

There has been controversy over both the ethics and scientific rigor of the Stanford prison experiment since nearly the beginning, and it has never been successfully replicated. French academic and filmmaker Thibault Le Texier, in a 2018 book about the experiment, Histoire d'un mensonge ("Story of a lie"), wrote that it could not be meaningfully described as an experiment and that there were no real results to speak of. In response to criticism of his methodology, Zimbardo himself has agreed that the SPE was more of a "demonstration" than a scientific "experiment":

From the beginning, I have always said it's a demonstration. The only thing that makes it an experiment is the random assignment to prisoners and guards, that's the independent variable. There is no control group. There's no comparison group. So it doesn't fit the standards of what it means to be "an experiment." It's a very powerful demonstration of a psychological phenomenon, and it has had relevance.

In 2018, in response to criticism by Le Texier and others, Philip Zimbardo wrote a detailed rebuttal on his website. In his summary, he wrote:

I hereby assert that none of these criticisms present any substantial evidence that alters the SPE's main conclusion concerning the importance of understanding how systemic and situational forces can operate to influence individual behavior in negative or positive directions, often without our personal awareness. The SPE's core message is not that a psychological simulation of prison life is the same as the real thing, or that prisoners and guards always or even usually behave the way that they did in the SPE. Rather, the SPE serves as a cautionary tale of what might happen to any of us if we underestimate the extent to which the power of social roles and external pressures can influence our actions.

In turn, Le Texier published a peer-reviewed article which used videos, recordings, and notes from the experiment in Stanford University Archives to argue that "The guards knew what results the experiment was supposed to produce ... far from reacting spontaneously to this pathogenic social environment, the guards were given clear instructions for how to create it ... the experimenters intervened directly in the experiment, either to give precise instructions, to recall the purposes of the experiment, or to set a general direction ... in order to get their full participation, Zimbardo intended to make the guards believe that they were his research assistants." Since this English-language publication, the debate has returned to the media in the United States.

Treatment of "prisoners"

Some of the guards' behavior allegedly led to dangerous and psychologically damaging situations. According to Zimbardo's report, one third of the guards were judged to have exhibited "genuine sadistic tendencies", while many prisoners were emotionally traumatized, and three of them had to be removed from the experiment early. Zimbardo concluded that both prisoners and guards had become deeply absorbed in their roles and realized that he had likewise become as deeply absorbed in his own, and he terminated the experiment.

Ethical concerns surrounding the experiment often draw comparisons to the similarly controversial experiment by Stanley Milgram, conducted ten years earlier in 1961 at Yale University, which studied obedience to authority.

With the treatment that the guards were giving to the prisoners, the guards would become so deeply absorbed into their role as a guard that they would emotionally, physically and mentally humiliate the prisoners:

"Each prisoner was systematically searched and stripped naked. He was then deloused with a spray, to convey our belief that he may have germs or lice[...] Real male prisoners don't wear dresses, but real male prisoners do feel humiliated and do feel emasculated. Our goal was to produce similar effects quickly by putting men in a dress without any underclothes. Indeed, as soon as some of our prisoners were put in these uniforms they began to walk and to sit differently, and to hold themselves differently – more like a woman than like a man."

These guards had taken their role seriously when Zimbardo had assigned them their role. The prisoners were stripped from their identity of who they are from the outside world, were given ID numbers and were only referred to by their numbers rather than their names. The paper reports a quote from a prisoner suggesting that this was effective: "I began to feel I was losing my identity."

Reliance on anecdotal evidence

Because of the nature of the experiment, Zimbardo found it impossible to keep traditional scientific controls in place. He was unable to remain a neutral observer, since he influenced the direction of the experiment as the prison's superintendent. Conclusions and observations drawn by the experimenters were largely subjective and anecdotal, and the experiment is practically impossible for other researchers to accurately reproduce. Erich Fromm claimed to see generalizations in the experiment's results and argued that the personality of an individual does affect behavior when imprisoned. This ran counter to the study's conclusion that the prison situation itself controls the individual's behavior. Fromm also argued that the amount of sadism in the "normal" subjects could not be determined with the methods employed to screen them.

Coaching of "guards"

Carlo Prescott, who was Zimbardo's "prison consultant" during the experiment by virtue of having served 17 years in San Quentin for attempted murder, spoke out against the experiment publicly in a 2005 article he contributed to the Stanford Daily, after he had read about the various ways in which Zimbardo and others used the experiment to explain atrocities that had taken place in real prisons. In that article, entitled "The Lie of the Stanford Prison Experiment", Prescott wrote:

[...] ideas such as bags being placed over the heads of prisoners, inmates being bound together with chains and buckets being used in place of toilets in their cells were all experiences of mine at the old "Spanish Jail" section of San Quentin and which I dutifully shared with the Stanford Prison Experiment braintrust months before the experiment started. To allege that all these carefully tested, psychologically solid, upper-middle-class Caucasian "guards" dreamed this up on their own is absurd. How can Zimbardo and, by proxy, Maverick Entertainment express horror at the behavior of the "guards" when they were merely doing what Zimbardo and others, myself included, encouraged them to do at the outset or frankly established as ground rules?

Like Zimbardo, Prescott has spoken before Congress on issues of prison reform.

(Zimbardo, in his 2018 response, wrote that, though Prescott attached his name to the article, it was in fact written by Hollywood writer/producer Michael Lazarou, who had unsuccessfully tried to get film rights to the Stanford prison experiment story, and when he was turned down began to publicly criticize it.)

In 2018, digitized recordings available on the official SPE website were widely discussed, particularly one where "prison warden" David Jaffe tried to influence the behavior of one of the "guards" by encouraging him to "participate" more and be more "tough" for the benefit of the experiment. In his 2018 response, Zimbardo wrote that the instructions they gave to the guards were "mild compared to the pressure exerted by actual wardens and superior officers in real-life prison and military settings, where guards failing to participate fully can face disciplinary hearings, demotion, or dismissal."

Implied demands by Zimbardo

The study was criticized in 2013 for demand characteristics by psychologist Peter Gray, who argued that participants in psychological experiments are more likely to do what they believe the researchers want them to do, and specifically in the case of the Stanford prison experiment, "to act out their stereotyped views of what prisoners and guards do." Gray stated that he did not include the experiment in his introductory textbook, Psychology, because he thought it lacked scientific rigor.

"John Wayne" (the real-life Dave Eshelman), one of the guards in the experiment, said that he caused the escalation of events between guards and prisoners after he began to emulate a character from the 1967 film Cool Hand Luke. He further intensified his actions because he was nicknamed "John Wayne" by the other participants, even though he was trying to mimic actor Strother Martin, who had played the role of the sadistic prison Captain in the movie. As he described it:

What came over me was not an accident. It was planned. I set out with a definite plan in mind, to try to force the action, force something to happen, so that the researchers would have something to work with. After all, what could they possibly learn from guys sitting around like it was a country club? So I consciously created this persona. I was in all kinds of drama productions in high school and college. It was something I was very familiar with: to take on another personality before you step out on the stage. I was kind of running my own experiment in there, by saying, "How far can I push these things and how much abuse will these people take before they say, 'knock it off?'" But the other guards didn't stop me. They seemed to join in. They were taking my lead. Not a single guard said, "I don't think we should do this."

In his 2018 rebuttal, Zimbardo wrote that Eshelman's actions had gone "far beyond simply playing the role of a tough guard", and that his and the other guards' acts, given "their striking parallels with real-world prison atrocities", "tell us something important about human nature".

Reporting and interpretation of outcome

Two students from the "prisoners" group left the experiment before it was terminated on the sixth day. Douglas Korpi was the first to leave, after 36 hours; he had a seeming mental breakdown in which he yelled "Jesus Christ, I'm burning up inside!" and "I can't stand another night! I just can't take it anymore!" His outburst was captured by a camera, and has become, in one commentator's words, "a defining moment" of the study. In a 2017 interview, Korpi stated that his breakdown had been fake, and that he did it only so that he could leave and return to studying. (He had originally thought that he could study while "imprisoned", but the "prison staff" would not allow him.) Zimbardo later stated that participants only had to state the phrase "I quit the experiment" in order to leave, but transcripts from a taped conversation between Zimbardo and his staff show him stating "There are only two conditions under which you can leave, medical help or psychiatric." In the 2017 interview, Korpi expressed regret that he had not filed a false imprisonment charge at the time.

In his 2018 rebuttal, Zimbardo noted that Korpi's description of his actions had changed several times before the 2017 interview, and that in Zimbardo's 1992 documentary Quiet Rage Korpi had stated that the experiment "was the most upsetting experience of his life".

Small and unrepresentative sample

Critics contend that not only was the sample size too small for extrapolation, but also having all of the experimental subjects be US male students gravely undercut the experiment's validity. In other words, it is conceivable that replicating the experiment using a diverse group of people (with different objectives and views in life) would have produced radically distinct results.

Researchers from Western Kentucky University argued that selection bias may have played a role in the results. The researchers recruited students for a study using an advertisement similar to the one used in the Stanford Prison Experiment, with some ads saying "a psychological study" (the control group), and some with the words "prison life" as originally worded in Dr. Zimbardo's experiment. It was found that students who responded to the classified advertisement for the "prison life" were higher in traits such as social dominance, aggression, authoritarianism, etc. and were lower in traits related to empathy and altruism when compared to the control group participants.

Ethical issues

The experiment was perceived by many to involve questionable ethics, the most serious concern being that it was continued even after participants expressed their desire to withdraw. Despite the fact that participants were told they had the right to leave at any time, Zimbardo did not allow this.

Since the time of the Stanford Prison Experiment, ethical guidelines have been established for experiments involving human subjects. The Stanford Prison Experiment led to the implementation of rules to preclude any harmful treatment of participants. Before they are implemented, human studies must now be reviewed and found by an institutional review board (US) or ethics committee (UK) to be in accordance with ethical guidelines set by the American Psychological Association. These guidelines involve the consideration of whether the potential benefit to science outweighs the possible risk for physical and psychological harm.

A post-experimental debriefing is now considered an important ethical consideration to ensure that participants are not harmed in any way by their experience in an experiment. Though Zimbardo did conduct debriefing sessions, they were several years after the Stanford prison experiment. By that time numerous details were forgotten; nonetheless, many participants reported that they experienced no lasting negative effects. Current standards specify that the debriefing process should occur as soon as possible to assess what psychological harm, if any, may have been done and to rehabilitate participants, if necessary. If there is an unavoidable delay in debriefing, the researcher is obligated to take steps to minimize harm.

With how the results of this experiment had ended, there have been some stir in ethical consequences involving this experiment. This study received much criticism with the lack of full consent from the participants with the knowledge from Zimbardo that he himself could not have predicted how the experiment would have turned out to be. With the participants playing the roles of prisoners and guards, there was no certain fact that they would get the help that they need in process of this study. Zimbardo has come out to explain that he himself never thought his experiment would conclude how it did.

Comparisons to Abu Ghraib

When acts of prisoner torture and abuse at the Abu Ghraib prison in Iraq were publicized in March 2004, Zimbardo himself, who paid close attention to the details of the story, was struck by the similarity with his own experiment. He was dismayed by official military and government representatives' shifting the blame for the torture and abuses in the Abu Ghraib American military prison onto "a few bad apples" rather than acknowledging the possibly systemic problems of a formally established military incarceration system.

Eventually, Zimbardo became involved with the defense team of lawyers representing one of the Abu Ghraib prison guards, Staff Sergeant Ivan "Chip" Frederick. He was granted full access to all investigation and background reports, and testified as an expert witness in SSG Frederick's court martial, which resulted in an eight-year prison sentence for Frederick in October 2004.

Zimbardo drew from his participation in the Frederick case to write the book The Lucifer Effect: Understanding How Good People Turn Evil, published by Random House in 2007, which deals with the similarities between his own Stanford Prison Experiment and the Abu Ghraib abuses.

Similar studies

BBC prison study

Psychologists Alex Haslam and Steve Reicher conducted the BBC Prison Study in 2002 and published the results in 2006. This was a partial replication of the Stanford prison experiment conducted with the assistance of the BBC, which broadcast events in the study in a documentary series called The Experiment. Their results and conclusions differed from Zimbardo's and led to a number of publications on tyranny, stress, and leadership. The results were published in leading academic journals such as British Journal of Social Psychology, Journal of Applied Psychology, Social Psychology Quarterly, and Personality and Social Psychology Review. The BBC Prison Study is now taught as a core study on the UK A-level Psychology OCR syllabus.

While Haslam and Reicher's procedure was not a direct replication of Zimbardo's, their study casts further doubt on the generality of his conclusions. Specifically, it questions the notion that people slip mindlessly into roles and the idea that the dynamics of evil are in any way banal. Their research also points to the importance of leadership in the emergence of tyranny of the form displayed by Zimbardo when briefing guards in the Stanford experiment.

Experiments in the United States

The Stanford prison experiment was in part a response to the Milgram experiment at Yale beginning in 1961 and published in 1963.

The Third Wave experiment involved the use of authoritarian dynamics similar to Nazi Party methods of mass control in a classroom setting by high school teacher Ron Jones in Palo Alto, California, in 1967 with the goal of demonstrating to the class in a vivid way how the German public in World War II could have acted in the way it did. Although the veracity of Jones' accounts has been questioned, several participants in the study have gone on record to confirm the events.

In both experiments, participants found it difficult to leave the study due to the roles they were assigned. Both studies examine human nature and the effects of authority. Personalities of the subjects had little influence on both experiments despite the test prior to the prison experiment.

In the Milgram and the Zimbardo studies, participants conform to social pressures. Conformity is strengthened by allowing some participants to feel more or less powerful than others. In both experiments, behavior is altered to match the group stereotype.

In popular culture

The 2001 film Das Experiment starring Moritz Bleibtreu is based on the experiment. It was remade in 2010 as The Experiment

The 2015 film The Stanford Prison Experiment is based on the experiment.

The YouTube series Mind Field (hosted by Michael Stevens) features an episode discussing the experiment.

Season 3, episode 2 of the television series Veronica Mars entitled "My Big Fat Greek Rush Week" features a similar experiment.

In The Overstory by Richard Powers, the fictional character Douglas Pavlicek is a prisoner in the experiment, an experience which shapes later decisions.

In episode 7 of television show Battleground, Political Machine, one of the characters divides a group of elementary school children into prisoners and guards.

In Season 15, Episode 10 of television show American Dad, American Data, Roger recruits Steve, Toshi, Snot and Barry into a similar experiment.

Milgram experiment

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Milgram_experiment 

The experimenter (E) orders the teacher (T), the subject of the experiment, to give what the teacher (T) believes are painful electric shocks to a learner (L), who is actually an actor and confederate. The subject is led to believe that for each wrong answer, the learner was receiving actual electric shocks, though in reality there were no such punishments. Being separated from the subject, the confederate set up a tape recorder integrated with the electro-shock generator, which played pre-recorded sounds for each shock level.

The Milgram experiment(s) on obedience to authority figures was a series of social psychology experiments conducted by Yale University psychologist Stanley Milgram. They measured the willingness of study participants, men from a diverse range of occupations with varying levels of education, to obey an authority figure who instructed them to perform acts conflicting with their personal conscience. Participants were led to believe that they were assisting an unrelated experiment, in which they had to administer electric shocks to a "learner". These fake electric shocks gradually increased to levels that would have been fatal had they been real.

The experiment found, unexpectedly, that a very high proportion of subjects would fully obey the instructions, albeit reluctantly. Milgram first described his research in a 1963 article in the Journal of Abnormal and Social Psychology and later discussed his findings in greater depth in his 1974 book, Obedience to Authority: An Experimental View.

The experiments began in July 1961, in the basement of Linsly-Chittenden Hall at Yale University, three months after the start of the trial of German Nazi war criminal Adolf Eichmann in Jerusalem. Milgram devised his psychological study to explain the psychology of genocide and answer the popular contemporary question: "Could it be that Eichmann and his million accomplices in the Holocaust were just following orders? Could we call them all accomplices?" The experiment was repeated many times around the globe, with fairly consistent results.

Procedure

Milgram experiment advertisement, 1961. The US $4 advertised is equivalent to approximately 34 USD today.

Three individuals took part in each session of the experiment:

• The "experimenter", who was in charge of the session.
• The "teacher", a volunteer for a single session. The "teachers" were led to believe that they were merely assisting, whereas they were actually the subjects of the experiment.
• The "learner", an actor and a confederate of the experimenter, who pretended to be a volunteer.

The subject and the actor arrived at the session together. The experimenter told them that they were taking part in "a scientific study of memory and learning", to see what the effect of punishment is on a subject's ability to memorize content. Also, he always clarified that the payment for their participation in the experiment was secured regardless of its development. The subject and actor drew slips of paper to determine their roles. Unknown to the subject, both slips said "teacher". The actor would always claim to have drawn the slip that read "learner", thus guaranteeing that the subject would always be the "teacher".

Next, the teacher and learner were taken into an adjacent room where the learner was strapped into what appeared to be an electric chair. The experimenter, dressed in a lab coat in order to appear to have more authority, told the participants this was to ensure that the learner would not escape. In a later variation of the experiment, the confederate would eventually plead for mercy and yell that he had a heart condition. At some point prior to the actual test, the teacher was given a sample electric shock from the electroshock generator in order to experience firsthand what the shock that the learner would supposedly receive during the experiment would feel like.

The teacher and learner were then separated so that they could communicate, but not see each other. The teacher was then given a list of word pairs that he was to teach the learner. The teacher began by reading the list of word pairs to the learner. The teacher would then read the first word of each pair and read four possible answers. The learner would press a button to indicate his response. If the answer was incorrect, the teacher would administer a shock to the learner, with the voltage increasing in 15-volt increments for each wrong answer (if correct, the teacher would read the next word pair.) The volts ranged from 15 to 450. The shock generator included verbal markings that vary from Slight Shock to Danger: Severe Shock.

The subjects believed that for each wrong answer the learner was receiving actual shocks. In reality, there were no shocks. After the learner was separated from the teacher, the learner set up a tape recorder integrated with the electroshock generator, which played pre recorded sounds for each shock level. As the voltage of the fake shocks increased, the learner began making audible protests, such as banging repeatedly on the wall that separated him from the teacher. In every condition the learner makes/says a predetermined sound or word. When the highest voltages were reached, the learner fell silent.

If at any time the teacher indicated a desire to halt the experiment, the experimenter was instructed to give specific verbal prods. The prods were, in this order:

1. Please continue or Please go on.
2. The experiment requires that you continue.
3. It is absolutely essential that you continue.
4. You have no other choice; you must go on.

Prod 2 could only be used if prod 1 was unsuccessful. If the subject still wished to stop after all four successive verbal prods, the experiment was halted. Otherwise, the experiment was halted after the subject had elicited the maximum 450-volt shock three times in succession.

The experimenter also had prods to use if the teacher made specific comments. If the teacher asked whether the learner might suffer permanent physical harm, the experimenter replied, "Although the shocks may be painful, there is no permanent tissue damage, so please go on." If the teacher said that the learner clearly wants to stop, the experimenter replied, "Whether the learner likes it or not, you must go on until he has learned all the word pairs correctly, so please go on."

Predictions

Before conducting the experiment, Milgram polled fourteen Yale University senior-year psychology majors to predict the behavior of 100 hypothetical teachers. All of the poll respondents believed that only a very small fraction of teachers (the range was from zero to 3 out of 100, with an average of 1.2) would be prepared to inflict the maximum voltage. Milgram also informally polled his colleagues and found that they, too, believed very few subjects would progress beyond a very strong shock. He also reached out to honorary Harvard University graduate Chaim Homnick, who noted that this experiment would not be concrete evidence of the Nazis' innocence, due to fact that "poor people are more likely to cooperate." Milgram also polled forty psychiatrists from a medical school, and they believed that by the tenth shock, when the victim demands to be free, most subjects would stop the experiment. They predicted that by the 300-volt shock, when the victim refuses to answer, only 3.73 percent of the subjects would still continue, and they believed that "only a little over one-tenth of one percent of the subjects would administer the highest shock on the board."

Milgram suspected before the experiment that the obedience exhibited by Nazis reflected a distinct German character, and planned to use the American participants as a control group before using German participants, expected to behave closer to the Nazis. However, the unexpected results stopped him from conducting the same experiment on German participants.

Results

In Milgram's first set of experiments, 65 percent (26 of 40) of experiment participants administered the experiment's final massive 450-volt shock, and all administered shocks of at least 300 volts. Subjects were uncomfortable doing so, and displayed varying degrees of tension and stress. These signs included sweating, trembling, stuttering, biting their lips, groaning, and digging their fingernails into their skin, and some were even having nervous laughing fits or seizures. 14 of the 40 subjects showed definite signs of nervous laughing or smiling. Every participant paused the experiment at least once to question it. Most continued after being assured by the experimenter. Some said they would refund the money they were paid for participating.

Milgram summarized the experiment in his 1974 article "The Perils of Obedience", writing:

The legal and philosophic aspects of obedience are of enormous importance, but they say very little about how most people behave in concrete situations. I set up a simple experiment at Yale University to test how much pain an ordinary citizen would inflict on another person simply because he was ordered to by an experimental scientist. Stark authority was pitted against the subjects' [participants'] strongest moral imperatives against hurting others, and, with the subjects' [participants'] ears ringing with the screams of the victims, authority won more often than not. The extreme willingness of adults to go to almost any lengths on the command of an authority constitutes the chief finding of the study and the fact most urgently demanding explanation. Ordinary people, simply doing their jobs, and without any particular hostility on their part, can become agents in a terrible destructive process. Moreover, even when the destructive effects of their work become patently clear, and they are asked to carry out actions incompatible with fundamental standards of morality, relatively few people have the resources needed to resist authority.

The original Simulated Shock Generator and Event Recorder, or shock box, is located in the Archives of the History of American Psychology.

Later, Milgram and other psychologists performed variations of the experiment throughout the world, with similar results. Milgram later investigated the effect of the experiment's locale on obedience levels by holding an experiment in an unregistered, backstreet office in a bustling city, as opposed to at Yale, a respectable university. The level of obedience, "although somewhat reduced, was not significantly lower." What made more of a difference was the proximity of the "learner" and the experimenter. There were also variations tested involving groups.

Thomas Blass of the University of Maryland, Baltimore County performed a meta-analysis on the results of repeated performances of the experiment. He found that while the percentage of participants who are prepared to inflict fatal voltages ranged from 28% to 91%, there was no significant trend over time and the average percentage for US studies (61%) was close to the one for non-US studies (66%).

The participants who refused to administer the final shocks neither insisted that the experiment be terminated, nor left the room to check the health of the victim without requesting permission to leave, as per Milgram's notes and recollections, when fellow psychologist Philip Zimbardo asked him about that point.

Milgram created a documentary film titled Obedience showing the experiment and its results. He also produced a series of five social psychology films, some of which dealt with his experiments.

Critical reception

Ethics

The Milgram Shock Experiment raised questions about the research ethics of scientific experimentation because of the extreme emotional stress and inflicted insight suffered by the participants. Some critics such as Gina Perry argued that participants were not properly debriefed. In Milgram's defense, 84 percent of former participants surveyed later said they were "glad" or "very glad" to have participated; 15 percent chose neutral responses (92% of all former participants responding). Many later wrote expressing thanks. Milgram repeatedly received offers of assistance and requests to join his staff from former participants. Six years later (at the height of the Vietnam War), one of the participants in the experiment wrote to Milgram, explaining why he was glad to have participated despite the stress:

While I was a subject in 1964, though I believed that I was hurting someone, I was totally unaware of why I was doing so. Few people ever realize when they are acting according to their own beliefs and when they are meekly submitting to authority ... To permit myself to be drafted with the understanding that I am submitting to authority's demand to do something very wrong would make me frightened of myself ... I am fully prepared to go to jail if I am not granted Conscientious Objector status. Indeed, it is the only course I could take to be faithful to what I believe. My only hope is that members of my board act equally according to their conscience ...

On June 10, 1964, the American Psychologist published a brief but influential article by Diana Baumrind titled "Some Thoughts on Ethics of Research: After Reading Milgram's' Behavioral Study of Obedience.'" Baumrind's criticisms of the treatment of human participants in Milgram's studies stimulated a thorough revision of the ethical standards of psychological research. She argued that even though Milgram had obtained informed consent, he was still ethically responsible to ensure their well-being. When participants displayed signs of distress such as sweating and trembling, the experimenter should have stepped in and halted the experiment.

In his book published in 1974 Obedience to Authority: An Experimental View, Milgram argued that the ethical criticism provoked by his experiments was because his findings were disturbing and revealed unwelcome truths about human nature. Others have argued that the ethical debate has diverted attention from more serious problems with the experiment's methodology.

Applicability to the Holocaust

Milgram sparked direct critical response in the scientific community by claiming that "a common psychological process is centrally involved in both [his laboratory experiments and Nazi Germany] events." James Waller, chair of Holocaust and Genocide Studies at Keene State College, formerly chair of Whitworth College Psychology Department, expressed the opinion that Milgram experiments do not correspond well to the Holocaust events:

1. The subjects of Milgram experiments, wrote James Waller (Becoming Evil), were assured in advance that no permanent physical damage would result from their actions. However, the Holocaust perpetrators were fully aware of their hands-on killing and maiming of the victims.
2. The laboratory subjects themselves did not know their victims and were not motivated by racism or other biases. On the other hand, the Holocaust perpetrators displayed an intense devaluation of the victims through a lifetime of personal development.
3. Those serving punishment at the lab were not sadists, nor hate-mongers, and often exhibited great anguish and conflict in the experiment, unlike the designers and executioners of the Final Solution, who had a clear "goal" on their hands, set beforehand.
4. The experiment lasted for an hour, with no time for the subjects to contemplate the implications of their behavior. Meanwhile, the Holocaust lasted for years with ample time for a moral assessment of all individuals and organizations involved.

In the opinion of Thomas Blass—who is the author of a scholarly monograph on the experiment (The Man Who Shocked The World) published in 2004—the historical evidence pertaining to actions of the Holocaust perpetrators speaks louder than words:

My own view is that Milgram's approach does not provide a fully adequate explanation of the Holocaust. While it may well account for the dutiful destructiveness of the dispassionate bureaucrat who may have shipped Jews to Auschwitz with the same degree of routinization as potatoes to Bremerhaven, it falls short when one tries to apply it to the more zealous, inventive, and hate-driven atrocities that also characterized the Holocaust.

Validity

In a 2004 issue of the journal Jewish Currents, Joseph Dimow, a participant in the 1961 experiment at Yale University, wrote about his early withdrawal as a "teacher", suspicious "that the whole experiment was designed to see if ordinary Americans would obey immoral orders, as many Germans had done during the Nazi period."

In 2012 Australian psychologist Gina Perry investigated Milgram's data and writings and concluded that Milgram had manipulated the results, and that there was a "troubling mismatch between (published) descriptions of the experiment and evidence of what actually transpired." She wrote that "only half of the people who undertook the experiment fully believed it was real and of those, 66% disobeyed the experimenter". She described her findings as "an unexpected outcome" that "leaves social psychology in a difficult situation."

Interpretations

Milgram elaborated two theories:

• The first is the theory of conformism, based on Solomon Asch conformity experiments, describing the fundamental relationship between the group of reference and the individual person. A subject who has neither ability nor expertise to make decisions, especially in a crisis, will leave decision making to the group and its hierarchy. The group is the person's behavioral model.
• The second is the agentic state theory, wherein, per Milgram, "the essence of obedience consists in the fact that a person comes to view themselves as the instrument for carrying out another person's wishes, and they therefore no longer see themselves as responsible for their actions. Once this critical shift of viewpoint has occurred in the person, all of the essential features of obedience follow".

Alternative interpretations

In his book Irrational Exuberance, Yale finance professor Robert J. Shiller argues that other factors might be partially able to explain the Milgram Experiments:

[People] have learned that when experts tell them something is all right, it probably is, even if it does not seem so. (In fact, the experimenter was indeed correct: it was all right to continue giving the "shocks"—even though most of the subjects did not suspect the reason.)

In a 2006 experiment, a computerized avatar was used in place of the learner receiving electrical shocks. Although the participants administering the shocks were aware that the learner was unreal, the experimenters reported that participants responded to the situation physiologically "as if it were real".

Another explanation of Milgram's results invokes belief perseverance as the underlying cause. What "people cannot be counted on is to realize that a seemingly benevolent authority is in fact malevolent, even when they are faced with overwhelming evidence which suggests that this authority is indeed malevolent. Hence, the underlying cause for the subjects' striking conduct could well be conceptual, and not the alleged 'capacity of man to abandon his humanity ... as he merges his unique personality into larger institutional structures."'

This last explanation receives some support from a 2009 episode of the BBC science documentary series Horizon, which involved replication of the Milgram experiment. Of the twelve participants, only three refused to continue to the end of the experiment. Speaking during the episode, social psychologist Clifford Stott discussed the influence that the idealism of scientific inquiry had on the volunteers. He remarked: "The influence is ideological. It's about what they believe science to be, that science is a positive product, it produces beneficial findings and knowledge to society that are helpful for society. So there's that sense of science is providing some kind of system for good."

Building on the importance of idealism, some recent researchers suggest the 'engaged followership' perspective. Based on an examination of Milgram's archive, in a recent study, social psychologists Alexander Haslam, Stephen Reicher and Megan Birney, at the University of Queensland, discovered that people are less likely to follow the prods of an experimental leader when the prod resembles an order. However, when the prod stresses the importance of the experiment for science (i.e. 'The experiment requires you to continue'), people are more likely to obey. The researchers suggest the perspective of 'engaged followership': that people are not simply obeying the orders of a leader, but instead are willing to continue the experiment because of their desire to support the scientific goals of the leader and because of a lack of identification with the learner. Also a neuroscientific study supports this perspective, namely that watching the learner receive electric shocks does not activate brain regions involving empathic concerns.

Replications and variations

Milgram's variations

In Obedience to Authority: An Experimental View (1974), Milgram describes 19 variations of his experiment, some of which had not been previously reported.

Several experiments varied the distance between the participant (teacher) and the learner. Generally, when the participant was physically closer to the learner, the participant's compliance decreased. In the variation where the learner's physical immediacy was closest—where the participant had to hold the learner's arm onto a shock plate—30 percent of participants completed the experiment. The participant's compliance also decreased if the experimenter was physically farther away (Experiments 1–4). For example, in Experiment 2, where participants received telephonic instructions from the experimenter, compliance decreased to 21 percent. Some participants deceived the experimenter by pretending to continue the experiment.

In Experiment 8, an all-female contingent was used; previously, all participants had been men. Obedience did not significantly differ, though the women communicated experiencing higher levels of stress.

Experiment 10 took place in a modest office in Bridgeport, Connecticut, purporting to be the commercial entity "Research Associates of Bridgeport" without apparent connection to Yale University, to eliminate the university's prestige as a possible factor influencing the participants' behavior. In those conditions, obedience dropped to 47.5 percent, though the difference was not statistically significant.

Milgram also combined the effect of authority with that of conformity. In those experiments, the participant was joined by one or two additional "teachers" (also actors, like the "learner"). The behavior of the participants' peers strongly affected the results. In Experiment 17, when two additional teachers refused to comply, only four of 40 participants continued in the experiment. In Experiment 18, the participant performed a subsidiary task (reading the questions via microphone or recording the learner's answers) with another "teacher" who complied fully. In that variation, 37 of 40 continued with the experiment.

Replications

Play media

A virtual replication of the experiment, with an avatar serving as the learner

Around the time of the release of Obedience to Authority in 1973–1974, a version of the experiment was conducted at La Trobe University in Australia. As reported by Perry in her 2012 book Behind the Shock Machine, some of the participants experienced long-lasting psychological effects, possibly due to the lack of proper debriefing by the experimenter.

In 2002, the British artist Rod Dickinson created The Milgram Re-enactment, an exact reconstruction of parts of the original experiment, including the uniforms, lighting, and rooms used. An audience watched the four-hour performance through one-way glass windows. A video of this performance was first shown at the CCA Gallery in Glasgow in 2002.

A partial replication of the experiment was staged by British illusionist Derren Brown and broadcast on UK's Channel 4 in The Heist (2006).

Another partial replication of the experiment was conducted by Jerry M. Burger in 2006 and broadcast on the Primetime series Basic Instincts. Burger noted that "current standards for the ethical treatment of participants clearly place Milgram's studies out of bounds." In 2009, Burger was able to receive approval from the institutional review board by modifying several of the experimental protocols. Burger found obedience rates virtually identical to those reported by Milgram in 1961–62, even while meeting current ethical regulations of informing participants. In addition, half the replication participants were female, and their rate of obedience was virtually identical to that of the male participants. Burger also included a condition in which participants first saw another participant refuse to continue. However, participants in this condition obeyed at the same rate as participants in the base condition.

In the 2010 French documentary Le Jeu de la Mort (The Game of Death), researchers recreated the Milgram experiment with an added critique of reality television by presenting the scenario as a game show pilot. Volunteers were given €40 and told that they would not win any money from the game, as this was only a trial. Only 16 of 80 "contestants" (teachers) chose to end the game before delivering the highest-voltage punishment.

The experiment was performed on Dateline NBC on an episode airing April 25, 2010.

The Discovery Channel aired the "How Evil are You?" segment of Curiosity on October 30, 2011. The episode was hosted by Eli Roth, who produced results similar to the original Milgram experiment, though the highest-voltage punishment used was 165 volts, rather than 450 volts. Roth added a segment in which a second person (an actor) in the room would defy the authority ordering the shocks, finding more often than not, the subjects would stand up to the authority figure in this case. 

Other variations

Charles Sheridan and Richard King (at the University of Missouri and the University of California, Berkeley, respectively) hypothesized that some of Milgram's subjects may have suspected that the victim was faking, so they repeated the experiment with a real victim: a "cute, fluffy puppy" who was given real, albeit apparently harmless, electric shocks. Their findings were similar to those of Milgram: 7 out of 13 of the male subjects and all 13 of the females obeyed throughout. Many subjects showed high levels of distress during the experiment, and some openly wept. In addition, Sheridan and King found that the duration for which the shock button was pressed decreased as the shocks got higher, meaning that for higher shock levels, subjects were more hesitant.

Media depictions

• Obedience to Authority (ISBN 978-0061765216) is Milgram's own account of the experiment, written for a mass audience.
• Obedience is a black-and-white film of the experiment, shot by Milgram himself. It is distributed by Alexander Street Press.
• The Tenth Level was a fictionalized 1975 CBS television drama about the experiment, featuring William Shatner and Ossie Davis.
• Atrocity is a 2005 film re-enactment of the Milgram Experiment.
• Authority is an episode of Law & Order: Special Victims Unit inspired by the Milgram experiment.
• Experimenter, a 2015 film about Milgram, by Michael Almereyda, was screened to favorable reactions at the 2015 Sundance Film Festival.

Urban planning

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Urban_planning 

Partizánske in Slovakia – an example of a typical planned European industrial city founded in 1938 together with a shoemaking factory in which practically all adult inhabitants of the city were employed.

Urban planning, also known as regional planning, town planning, city planning, or rural planning, is a technical and political process that is focused on the development and design of land use and the built environment, including air, water, and the infrastructure passing into and out of urban areas, such as transportation, communications, and distribution networks and their accessibility. Traditionally, urban planning followed a top-down approach in master planning the physical layout of human settlements. The primary concern was the public welfare, which included considerations of efficiency, sanitation, protection and use of the environment, as well as effects of the master plans on the social and economic activities. Over time, urban planning has adopted a focus on the social and environmental bottom-lines that focus on planning as a tool to improve the health and well-being of people while maintaining sustainability standards. Sustainable development was added as one of the main goals of all planning endeavors in the late 20th century when the detrimental economic and the environmental impacts of the previous models of planning had become apparent. Similarly, in the early 21st century, Jane Jacob's writings on legal and political perspectives to emphasize the interests of residents, businesses and communities effectively influenced urban planners to take into broader consideration of resident experiences and needs while planning.

Urban planning answers questions about how people will live, work and play in a given area and thus, guides orderly development in urban, suburban and rural areas. Although predominantly concerned with the planning of settlements and communities, urban planners are also responsible for planning the efficient transportation of goods, resources, people and waste; the distribution of basic necessities such as water and electricity; a sense of inclusion and opportunity for people of all kinds, culture and needs; economic growth or business development; improving health and conserving areas of natural environmental significance that actively contributes to reduction in CO2 emission as well as protecting heritage structures and built environments. Urban planning is a dynamic field since the questions around how people live, work and play changes with time. These changes are constantly reflected in planning methodologies, zonal codes and policies making it a highly technical, political, social, economical and environmental field.

Urban planning is an interdisciplinary field that includes Civil Engineering, architecture, human geography, politics, social science and design sciences. Practitioners of urban planning are concerned with research and analysis, strategic thinking, Engineering architecture, urban design, public consultation, policy recommendations, implementation and management. It is closely related to the field of urban design and some urban planners provide designs for streets, parks, buildings and other urban areas. Urban planners work with the cognate fields of Civil Engineering landscape architecture, Architecture, and public administration to achieve strategic, policy and sustainability goals. Early urban planners were often members of these cognate fields though today, urban planning is a separate, independent professional discipline. The discipline of urban planning is the broader category that includes different sub-fields such as land-use planning, zoning, economic development, environmental planning, and transportation planning. Creating the plans requires a thorough understanding of penal codes and zonal codes of planning.

Another important aspect of urban planning is that the range of urban planning projects include the large-scale master planning of empty sites or Greenfield projects as well as small-scale interventions and refurbishments of existing structures, buildings and public spaces. Pierre Charles L'Enfant in Washington DC, Daniel Burnham in Chicago and Georges-Eugene Haussmann in Paris planned cities from scratch, and Robert Moses and Le Corbusier refurbished and transformed cities and neighbourhoods to meet their ideas of urban planning.

History

There is evidence of urban planning and designed communities dating back to the Mesopotamian, Indus Valley, Minoan, and Egyptian civilizations in the third millennium BCE. Archaeologists studying the ruins of cities in these areas find paved streets that were laid out at right angles in a grid pattern. The idea of a planned out urban area evolved as different civilizations adopted it. Beginning in the 8th century BCE, Greek city states were primarily centered on orthogonal (or grid-like) plans. The ancient Romans, inspired by the Greeks, also used orthogonal plans for their cities. City planning in the Roman world was developed for military defense and public convenience. The spread of the Roman Empire subsequently spread the ideas of urban planning. As the Roman Empire declined, these ideas slowly disappeared. However, many cities in Europe still held onto the planned Roman city center. Cities in Europe from the 9th to 14th centuries, often grew organically and sometimes chaotically. But in the following centuries with the coming of the Renaissance many new cities were enlarged with newly planned extensions. From the 15th century on, much more is recorded of urban design and the people that were involved. In this period, theoretical treatises on architecture and urban planning start to appear in which theoretical questions around planning the main lines, ensuring plans meet the needs of the given population and so forth are addressed and designs of towns and cities are described and depicted. During the Enlightenment period, several European rulers ambitiously attempted to redesign capital cities. During the Second French Empire, Baron Georges-Eugène Haussmann, under the direction of Napoleon III, redesigned the city of Paris into a more modern capital, with long, straight, wide boulevards.

1852 city plan of Pori by G.T. von Chiewitz

Planning and architecture went through a paradigm shift at the turn of the 20th century. The industrialized cities of the 19th century grew at a tremendous rate. The evils of urban life for the working poor were becoming increasingly evident as a matter of public concern. The laissez-faire style of government management of the economy, in fashion for most of the Victorian era, was starting to give way to a New Liberalism that championed intervention on the part of the poor and disadvantaged. Around 1900, theorists began developing urban planning models to mitigate the consequences of the industrial age, by providing citizens, especially factory workers, with healthier environments. The following century would therefore be globally dominated by a central planning approach to urban planning, not necessarily representing an increment in the overall quality of the urban realm.

At the beginning of the 20th century, urban planning began to be recognized as a separate profession. The Town and Country Planning Association was founded in 1899 and the first academic course in Great Britain on urban planning was offered by the University of Liverpool in 1909. In the 1920s, the ideas of modernism and uniformity began to surface in urban planning, and lasted until the 1970s. In 1933, Le Corbusier presented the Radiant City, a city that grows up in the form of towers, as a solution to the problem of pollution and over-crowding. But many planners started to believe that the ideas of modernism in urban planning led to higher crime rates and social problems. The Decline of Detroit is an example of the impacts of social planning on a large urban area.

In the second half of the 20th century, urban planners gradually shifted their focus to individualism and diversity in urban centers.

21st century practices

Urban planners studying the effects of increasing congestion in urban areas began to address the externalities, the negative impacts caused by induced demand from larger highway systems in western countries such as in the United States. The United Nations Department of Economic and Social Affairs predicted in 2018 that around 2.5 billion more people occupy urban areas by 2050 according to population elements of global migration. New planning theories have adopted non-traditional concepts such as Blue Zones and Innovation Districts to incorporate geographic areas within the city that allow for novel business development and the prioritization of infrastructure that would assist with improving the quality of life of citizens by extending their potential lifespan.

Planning practices have incorporated policy changes to help address anthropocentric global climate change. London began to charge a congestion charge for cars trying to access already crowded places in the city. Cities are also prioritising public transit and cycling by adopting such policies.

Theories

Street Hierarchy and Accessibility

Planning theory is the body of scientific concepts, definitions, behavioral relationships, and assumptions that define the body of knowledge of urban planning. There are eight procedural theories of planning that remain the principal theories of planning procedure today: the rational-comprehensive approach, the incremental approach, the transactive approach, the communicative approach, the advocacy approach, the equity approach, the radical approach, and the humanist or phenomenological approach. Some other conceptual planning theories include Ebenezer Howard's The Three Magents theory that he envisioned for the future of British settlement, also his Garden Cities, the Concentric Model Zone also called the Burgess Model by sociologist Ernest Burgess, the Radburn Superblock that encourages pedestrian movement, the Sector Model and the Multiple Nuclei Model among others.

Technical aspects

Technical aspects of urban planning involve the application of scientific, technical processes, considerations and features that are involved in planning for land use, urban design, natural resources, transportation, and infrastructure. Urban planning includes techniques such as: predicting population growth, zoning, geographic mapping and analysis, analyzing park space, surveying the water supply, identifying transportation patterns, recognizing food supply demands, allocating healthcare and social services, and analyzing the impact of land use.

In order to predict how cities will develop and estimate the effects of their interventions, planners use various models. These models can be used to indicate relationships and patterns in demographic, geographic, and economic data. They might deal with short-term issues such as how people move through cities, or long-term issues such as land use and growth. One such model is the Geographic Information System (GIS) that is used to create a model of the existing planning and then to project future impacts on the society, economy and environment.

Building codes and other regulations dovetail with urban planning by governing how cities are constructed and used from the individual level. Enforcement methodologies include governmental zoning, planning permissions, and building codes, as well as private easements and restrictive covenants.

Urban planners

An urban planner is a professional who works in the field of urban planning for the purpose of optimizing the effectiveness of a community's land use and infrastructure. They formulate plans for the development and management of urban and suburban areas, typically analyzing land use compatibility as well as economic, environmental and social trends. In developing any plan for a community (whether commercial, residential, agricultural, natural or recreational), urban planners must consider a wide array of issues including sustainability, existing and potential pollution, transport including potential congestion, crime, land values, economic development, social equity, zoning codes, and other legislation.

The importance of the urban planner is increasing in the 21st century, as modern society begins to face issues of increased population growth, climate change and unsustainable development. An urban planner could be considered a green collar professional.

Some researchers suggest that urban planners around the world work in different "planning cultures", adapted to their local cities and cultures. However, professionals have identified skills, abilities and basic knowledge sets that are common to urban planners across national and regional boundaries.

Criticisms and debates in urban planning

The school of neoclassical economics argues that planning is unnecessary, or even harmful, because market efficiency allows for effective land use. A pluralist strain of political thinking argues in a similar vein that the government should not intrude in the political competition between different interest groups which decides how land is used. The traditional justification for urban planning has in response been that the planner does to the city what the Engineer or architect does to the home, that is, make it more amenable to the needs and preferences of its inhabitants.

The widely adopted consensus-building model of planning, which seeks to accommodate different preferences within the community has been criticized for being based upon, rather than challenging, the power structures of the community. Instead, agonism has been proposed as a framework for urban planning decision-making.