In psychology, the Asch conformity experiments or the Asch paradigm were a series of studies directed by Solomon Asch studying if and how individuals yielded to or defied a majority group and the effect of such influences on beliefs and opinions.    
Developed in the 1950s, the methodology remains in use by many researchers. Uses include the study of conformity effects of task importance,  age,  sex,     and culture.  
Many early studies in social psychology were adaptations of earlier work on "suggestibility" whereby researchers such as Edward L. Thorndyke were able to shift the preferences of adult subjects towards majority or expert opinion.  Still the question remained as to whether subject opinions were actually able to be changed, or if such experiments were simply documenting a Hawthorne effect in which participants simply gave researchers the answers they wanted to hear. Solomon Asch's experiments on group conformity mark a departure from these earlier studies by removing investigator influence from experimental conditions.
In 1951, Asch conducted his first conformity laboratory experiments at Swarthmore College, laying the foundation for his remaining conformity studies. The experiment was published on two occasions.  
Groups of eight male college students participated in a simple "perceptual" task. In reality, all but one of the participants were actors, and the true focus of the study was about how the remaining participant would react to the actors' behavior.
The actors knew the true aim of the experiment, but were introduced to the subject as other participants. Each student viewed a card with a line on it, followed by another with three lines labeled A, B, and C (see accompanying figure). One of these lines was the same as that on the first card, and the other two lines were clearly longer or shorter (i.e., a near-100% rate of correct responding was expected). Each participant was then asked to say aloud which line matched the length of that on the first card. Before the experiment, all actors were given detailed instructions on how they should respond to each trial (card presentation). They would always unanimously nominate one comparator, but on certain trials they would give the correct response and on others, an incorrect response. The group was seated such that the real participant always responded last.
Subjects completed 18 trials. On the first two trials, both the subject and the actors gave the obvious, correct answer. On the third trial, the actors would all give the same wrong answer. This wrong-responding recurred on 11 of the remaining 15 trials. It was subjects' behavior on these 12 "critical trials" (the 3rd trial + the 11 trials where the actors gave the same wrong answer) that formed the aim of the study: to test how many subjects would change their answer to conform to those of the 7 actors, despite it being wrong. Subjects were interviewed after the study including being debriefed about the true purpose of the study. These post-test interviews shed valuable light on the study: both because they revealed subjects often were "just going along" and because they revealed considerable individual differences to Asch. Additional trials with slightly altered conditions were also run,  including having a single actor also give the correct answer.
Asch's experiment also had a condition in which participants were tested alone with only the experimenter in the room. In total, there were 50 subjects in the experimental condition and 37 in the control condition.
In the control group, with no pressure to conform to actors, the error rate on the critical stimuli was less than 1%. 
In the actor condition also, the majority of participants' responses remained correct (63.2%), but a sizable minority of responses conformed to the actors' (incorrect) answer (36.8 percent). The responses revealed strong individual differences: Only 5 percent of participants were always swayed by the crowd. 25 percent of the sample consistently defied majority opinion, with the rest conforming on some trials. An examination of all critical trials in the experimental group revealed that one-third of all responses were incorrect. These incorrect responses often matched the incorrect response of the majority group (i.e., actors). Overall, 75% of participants gave at least one incorrect answer out of the 12 critical trials.  In his opinion regarding the study results, Asch put it this way: "That intelligent, well-meaning, young people are willing to call white black is a matter of concern."
Participants' interview responses revealed a complex mixture of individual differences in subjects' reaction to the experimental situation, with distinct reactions linked to factors such as confidence, self-doubt, the desire to be normative, and resolving perceived confusion over the nature of the task.
Asch's report included interviews of a subject that remained "independent" and another that "yielded." Each provided a descriptive account following disclosure of the true nature of the experiment. The "independent" subject said that he felt happy and relieved and added, "I do not deny that at times I had the feeling: 'to go with it, I'll go along with the rest.'" (page 182)  At the other end of the spectrum, one "yielding" subject (who conformed in 11 of 12 critical trials) said, "I suspected about the middle – but tried to push it out of my mind." (page 182)  Asch points out that although the "yielding" subject was suspicious, he was not sufficiently confident to go against the majority.
Subjects who did not conform to the majority reacted either with "confidence": they experienced conflict between their idea of the obvious answer and the group's incorrect answer, but stuck with their own answer, or were "withdrawn". These latter subjects stuck with their perception but did not experience conflict in doing so. Some participants also exhibited "doubt", responding in accordance with their perception, but questioning their own judgment while nonetheless sticking to their (correct) response, expressing this as needing to behave as they had been asked to do in the task.
Participants who conformed to the majority on at least 50% of trials reported reacting with what Asch called a "distortion of perception". These participants, who made up a distinct minority (only 12 subjects), expressed the belief that the actors' answers were correct, and were apparently unaware that the majority were giving incorrect answers.
Among the other participants who yielded on some trials, most expressed what Asch termed "distortion of judgment". These participants concluded after a number of trials that they must be wrongly interpreting the stimuli and that the majority must be right, leading them to answer with the majority. These individuals were characterized by low levels of confidence. The final group of participants who yielded on at least some trials exhibited a "distortion of action". These subjects reported that they knew what the correct answer was, but conformed with the majority group simply because they didn't want to seem out of step by not going along with the rest.  All conforming respondents underestimated the frequency with which they conformed to the majority. 
In subsequent research experiments, Asch explored several variations on the paradigm from his 1951 study. 
In 1955 he reported on work with 123 male students from three different universities.  A second paper in 1956 also consisted of 123 male college students from three different universities,:  Asch did not state if this was in fact the same sample as reported in his 1955 paper: The principal difference is that the 1956 paper includes an elaborate account of his interviews with participants. Across all these papers, Asch found the same results: participants conformed to the majority group in about one-third of all critical trials.
The Asch conformity experiments are often interpreted as evidence for the power of conformity and normative social influence,    where normative influence is the willingness to conform publicly to attain social reward and avoid social punishment.  From this perspective, the results are viewed as a striking example of people publicly endorsing the group response despite knowing full well that they were endorsing an incorrect response.  
In contrast, John Turner and colleagues argue that the interpretation of the Asch conformity experiments as normative influence is inconsistent with the data.    They point out that post-experiment interviews revealed that participants experienced uncertainty about their judgement during the experiments. Although the correct answer appeared obvious to the researchers, this was not necessarily the experience of participants. Subsequent research has demonstrated similar patterns of conformity where participants were anonymous and thus not subject to social punishment or reward on the basis of their responses.  From this perspective, the Asch conformity experiments are viewed as evidence for the self-categorization theory account of social influence (otherwise known as the theory of referent informational influence).       Here, the observed conformity is an example of depersonalization processes, whereby people expect to hold the same opinions as others in their ingroup and will often adopt those opinions.
The conformity demonstrated in Asch experiments may contradict aspects of social comparison theory.    Social comparison theory suggests that, when seeking to validate opinions and abilities, people will first turn to direct observation. If direct observation is ineffective or not available, people will then turn to comparable others for validation.  In other words, social comparison theory predicts that social reality testing will arise when physical reality testing yields uncertainty. The Asch conformity experiments demonstrate that uncertainty can arise as an outcome of social reality testing. More broadly, this inconsistency has been used to support the position that the theoretical distinction between social reality testing and physical reality testing is untenable.    
Asch's 1956 report emphasized the predominance of independence over yielding saying "the facts that were being judged were, under the circumstances, the most decisive."  However, a 1990 survey of US social psychology textbooks found that most ignored independence, instead reported a misleading summary of the results as reflecting complete power of the situation to produce conformity of behavior and belief. 
A 2015 survey found no change, with just 1 of 20 major texts reporting that most participant-responses defied majority opinion. No text mentioned that 95% of subjects defied the majority at least once. Nineteen of the 20 books made no mention of Asch's interview data in which many participants said they were certain all along that the actors were wrong.  This portrayal of the Asch studies was suggested to fit with social psychology narratives of situationism, obedience and conformity, to the neglect of recognition of disobedience of immoral commands (e.g., disobedience shown by participants in Milgram Studies), desire for fair treatment (e.g., resistance to tyranny shown by many participants in the Stanford prison studies) and self-determination. 
The Milgram experiment(s) on obedience to authority figures were a series of social psychology experiments conducted by Yale University psychologist Stanley Milgram. They measured the willingness of study participants, 40 men in the age range of 20 to 50 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.
Social psychology is the scientific study of how thoughts, feelings, and behaviors are influenced by the real or imagined presence of other people or by social norms. Social psychologists typically explain human behavior as a result of the relationship between mental states and social situations, studying the social conditions under which thoughts, feelings, and behaviors occur, and how these variables influence social interactions.
Solomon Eliot Asch (September 14, 1907 – February 20, 1996) was a Polish-American Gestalt psychologist and pioneer in social psychology. He created seminal pieces of work in impression formation, prestige suggestion, conformity, and many other topics. His work follows a common theme of Gestalt psychology that the whole is not only greater than the sum of its parts, but the nature of the whole fundamentally alters the parts. Asch stated: "Most social acts have to be understood in their setting, and lose meaning if isolated. No error in thinking about social facts is more serious than the failure to see their place and function". Asch is most well known for his conformity experiments, in which he demonstrated the influence of group pressure on opinions. A Review of General Psychology survey, published in 2002, ranked Asch as the 41st most cited psychologist of the 20th century.
Human subject research is systematic, scientific investigation that can be either interventional or observational and involves human beings as research subjects, commonly known as test subjects. Human subject research can be either medical (clinical) research or non-medical research. Systematic investigation incorporates both the collection and analysis of data in order to answer a specific question. Medical human subject research often involves analysis of biological specimens, epidemiological and behavioral studies and medical chart review studies. On the other hand, human subject research in the social sciences often involves surveys which consist of questions to a particular group of people. Survey methodology includes questionnaires, interviews, and focus groups.
The spiral of silence theory is a political science and mass communication theory proposed by the German political scientist Elisabeth Noelle-Neumann. It states that an individual's perception of the distribution of public opinion influences that individual's willingness to express their own opinions, which in turn affects the perceptions and, ultimately, willingness of others to express their opinions. The main idea is that people influence each other's willingness to express opinions through social interaction. According to the spiral of silence theory, individuals will be more confident and outward with their opinion when they notice that their personal opinion is shared throughout a group. But if the individual notices that their opinion is unpopular with the group they will be more inclined to be reserved and remain silent. In other words, from the individual's perspective, "not isolating himself is more important than his own judgement", meaning his perception of how others in the group perceive him is more important to himself than the need for his opinion to be heard.
Social influence comprises the ways in which individuals adjust their behavior to meet the demands of a social environment. It takes many forms and can be seen in conformity, socialization, peer pressure, obedience, leadership, persuasion, sales, and marketing. Typically social influence results from a specific action, command, or request, but people also alter their attitudes and behaviors in response to what they perceive others might do or think. In 1958, Harvard psychologist Herbert Kelman identified three broad varieties of social influence.
Social proof is a psychological and social phenomenon wherein people copy the actions of others in choosing how to behave in a given situation. The term was coined by Robert Cialdini in his 1984 book Influence: Science and Practice, and the concept is also known as informational social influence.
Herd, mob, or pack mentality describes how people can be influenced by the majority.
Attitudes are associated beliefs and behaviors towards some object. They are not stable, and because of the communication and behavior of other people, are subject to change by social influences, as well as by the individual's motivation to maintain cognitive consistency when cognitive dissonance occurs—when two attitudes or attitude and behavior conflict. Attitudes and attitude objects are functions of affective and cognitive components. It has been suggested that the inter-structural composition of an associative network can be altered by the activation of a single node. Thus, by activating an affective or emotional node, attitude change may be possible, though affective and cognitive components tend to be intertwined.
Minority influence, a form of social influence, takes place when a member of a minority group influences the majority to accept the minority's beliefs or behavior. This occurs when a small group or an individual acts as an agent of social change by questioning established societal perceptions, and proposing alternative, original ideas which oppose the existing social norms. There are two types of social influence: majority influence and minority influence. Majority influence refers to the majority trying to produce conformity on the minority, while minority influence is converting the majority to adopt the thinking of the minority group. Unlike other forms of influence, minority influence is often thought of as a more innovative form of social change, because it usually involves a personal shift in private opinion. Examples of minority influence include the civil rights movement in the United States and the anti-apartheid movement in South Africa.
Social impact theory was created by Bibb Latané in 1981 and consists of four basic rules which consider how individuals can be "sources or targets of social influence". Social impact is the result of social forces including the strength of the source of impact, the immediacy of the event, and the number of sources exerting the impact. The more targets of impact that exist, the less impact each individual target has.
Normative social influence is a type of social influence that leads to conformity. It is defined in social psychology as "...the influence of other people that leads us to conform in order to be liked and accepted by them." The power of normative social influence stems from the human identity as a social being, with a need for companionship and association.
Compliance is a response—specifically, a submission—made in reaction to a request. The request may be explicit or implicit. The target may or may not recognize that they are being urged to act in a particular way.
Conformity is the act of matching attitudes, beliefs, and behaviors to group norms, politics or being like-minded. Norms are implicit, specific rules, shared by a group of individuals, that guide their interactions with others. People often choose to conform to society rather than to pursue personal desires - because it is often easier to follow the path others have made already, rather than forging a new one. Thus, conformity is sometimes a product of group communication. This tendency to conform occurs in small groups and/or in society as a whole and may result from subtle unconscious influences, or from direct and overt social pressure. Conformity can occur in the presence of others, or when an individual is alone. For example, people tend to follow social norms when eating or when watching television, even if alone.
Memory conformity, also known as social contagion of memory, refers to the phenomenon where memories or information reported by others influences an individual and is incorporated into the individual's memory. Memory conformity is a memory error due to both social influences and cognitive mechanisms. Social contamination of false memory can be exemplified in prominent situations involving social interactions, such as eyewitness testimony. Research on memory conformity has revealed that such suggestibility and errors with source monitoring has far reaching consequences, with important legal and social implications.
A social experiment is a type of psychological or sociological research for testing people's reactions to certain situations or events. The experiment depends on a particular social approach where the main source of information is the participants' point of view and knowledge. To carry out a social experiment, specialists usually split participants into two groups — active participants and respondents. Throughout the experiment, specialists monitor participants to identify the effects and differences resulting from the experiment. Intentional communities are generally considered social experiments.
An argument from authority, also called an appeal to authority, or argumentum ad verecundiam, is a form of argument in which the opinion of an authority on a topic is used as evidence to support an argument. Some consider that it is used in a cogent form if all sides of a discussion agree on the reliability of the authority in the given context, and others consider it to be a fallacy to cite the views of an authority on the discussed topic as a means of supporting an argument.
Anticonformity (counterconformity) refers to when an individual consciously and deliberately challenges the position or actions of the group. Anticonformity is not merely the absence of conformity. Anticonformity can be a response to certain context and social pressure or expectations. Anticonformity commonly takes place in a group environment where other individuals might differ in opinion. Individuals who display anticonformity behaviours are internally motivated to disrupt the balance of the group. Further, anticonformist individuals are motivated by rebelliousness and are not influenced by social forces or norms. Anticonformity has been labelled a dependent behaviour as its manifestation is dependent on the group’s position in regard to an event or situation.
Interpersonal influence is a type of social influence which results from group members encouraging, or forcing, conformity while discouraging, and possibly punishing, nonconformity. It is one of three types of social influences that lead people to conform to the majority, or the group's norms. The other two types are influence are informational influence and normative influence.
The Crutchfield Situation was an experimental procedure and apparatus created by Richard S. Crutchfield in 1955 to study conformity. Essentially, the Crutchfield Situation was an attempt to improve upon the methodology employed in the Asch conformity experiments. One of the major criticisms concerning the Asch studies was the need for many accomplices in order to study one participant. According to Forsyth, an additional criticism of Asch's design was that “participants in the Asch studies stated their choices aloud under the watchful eyes of all the other members, and this procedure likely increased their feelings of embarrassment and of being evaluated.”