Which of the following concepts was advanced by social psychologists to explain why people who are part of a crowd sometimes commit aggressive antisocial acts that they would not commit if they were alone
a. groupthinkb. cognitive dissonancec. social facilitationd. deindividuatione. catharsis

d) Deindividuation

Explanation:

Deindividuation is defined as trait through which the identity of a person is set aside as an individual when compared to his own identity in group environment. It restricts the critical thinking and overrides self awareness of person.

Usually in this type of case, behavior and feeling of person in a group matter more while identification rather than as an individual person.

According to the situation mentioned in the question, people act with antisocial behavior in group which they would not present as individual because of deindividuation.

Other options are incorrect because group-think is thinking of members in a group for making decision.Cognitive dissonance invokes non-stable feeling and thought .

Catharsis is process for feeling relieved.Social facilitation is process of searching people whose presence make a person perform better.

Thus, the correct option is option(d).

its so obvious. its 999 obviously.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.