The statement is TRUE.
In 1951 Solomon Asch carried out the famous Conformity Experiments, set out to measure the dynamics of group-thinking. He presented his subjects with an extremely simple judgement task with a very obvious answer, joined by a previously prepared group that was told to answer incorrectly on purpose. By making it so simple, it would be clear that any subject that answered incorrectly would be doing it because of group pressure. With this first experiment, Asch proved a correlation between a group's influence on an individual's conformity.
Further trials went deeper into which factors were the most impactful to influence conformity. The results showed that increasing group size by up to three times, raised the conformity levels to 32%. However, larger groups did not impact this number. Applying group unanimity, on the other hand, showed an increase of as much as 80% on the conformity rates.
This clarified how much bigger of an influence unanimity was over group size, meaning it mattered more to an individual if an entire group agreed on something (even if the group was small), over a larger majority's opinion when a group was more split-up.
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