Jenness (1932)

Aim: To investigate whether people would change their beliefs in an ambiguous situation where the correct answer was unclear.

Method: Jenness asked 26 student participants to estimate the number of white beans in a glass bottle. The bottle contained 811 beans. Each participant first gave an individual estimate. The participants were then placed into groups of three and given the opportunity to discuss their answers. After the discussion, each group produced a group estimate. Finally, the participants were asked to give a second individual estimate. This allowed Jenness to see whether they would change their original answer after hearing the views of other group members.

Results: The mean estimates before and after the group discussion, for both males and females, are shown below:

Jenness found that:

• most participants changed their original estimates after the group discussion

• female participants changed their estimates by a larger amount, on average, than male participants

• the range of estimates fell from 1,875 before discussion to 474 after discussion (a 75% reduction), showing that the estimates became much more similar after group discussion

Conclusion: Jenness concluded that participants changed their estimates because they believed the group's judgement was more likely to be correct. This supports the notion of informational social influence, as the task was ambiguous and participants used the opinions of others as a source of information. In addition, because the final estimates were given individually, the findings are less likely to be explained by normative social influence, since participants were not simply changing their answers to fit in but to be right.