Evaluation: Research support for ISI (strength)
There's research to support ISI.
Lucas et al found that ppts confirmed more often to incorrect answers they were given when the maths problems were difficult.
This is because when the problems were easy the ppts 'knew their own minds' but when the problems were hard the situation became ambiguous (clear).
Ppts didn't want to be wrong, so they relied on the answers they were given.
Shows that ISI is a valid explanation of conformity because the results are what ISI would predict.