ConformityWe conform to the choices of the people around us

Participants are told they are taking part in a vision test

They are seated in a room with other ‘participants’ taking part in the same test

These people are actually stooges

Participant

StoogeStoogeStoogeStooge

Every participant is shown a line…

Every participant is shown a line… …and then asked to choose the matching line from a group of three lines of different lengths

A B C

Each participant is asked to individually select the matching line and give their answer out loud to the group…

A B C

I think it’s ‘C’I think it’s ‘C’I think it’s ‘C’I think it’s ‘C’

I think it’s ‘C’

Occasionally the stooges unanimously declare a different line is the correct match…

I know it’s ‘C’ I think it’s ‘B’I think it’s ‘B’I think it’s ‘B’I think it’s ‘B’

Err… I think it’s ‘B’ too

I think it’s ‘B’I think it’s ‘B’I think it’s ‘B’I think it’s ‘B’

Participants conform to the group answer about a third of the time, even when they report afterwards that they knew the answer was wrong

In a control group where everyone writes down their answers privately, participants chose the correct line 98% of the time

Why?

1. People want to fit in with the rest of the group — giving a different answer puts them at risk of being singled-out

2. Some people also believe the group is better informed than they are, so they change their mind

Reference

Effects of group pressure on the modification and distortion of judgements; Asch, S. E. in H. Guetzkow (ed.) Groups, leadership and men. (1951) Pittsburgh, PA: Carnegie Press.