Group Size Effects on Conformity

A field experiment is reported which tests the hypothesis that conformity is an increasing concave downward function of the numerosity of a unanimous influence source. Thirty-three student Es presented petitions containing zero, four, eight, or 12 previous signatures to 300 male and female college students. The probability of signing increased from zero to four signatures, then leveled off. These results, as well as those of two pilot studies, generally support the hypothesis. A two factor theory of the effects of group size on conformity is proposed.