Anonymity of votes is not needed if everyone in the group has the same interest. However, if someone from the group wants to win something for themselves, then transparency begins to be a problem. With open voting, a selfish person can:
– see who their ally
is- see if allies voted as they agreed
– pressure people who vote differently
The influence of peer pressure on decisions is well illustrated by Asch's experiment. It is very difficult to have a different opinion than the people around. 75% of the surveyed people succumbed to peer pressure at least once. Only 25% of respondents resisted this pressure.
There are two ways to defend yourself from peer pressure – one is the presence of a friend who has an opinion like you and the other is anonymity.