Individual decisions are often influenced by a variety of subtle factors which people can see affecting others’ decisions but fail to see affecting their own.
People are more likely to choose the things they see very often even if they do not realize how often they see them.
Individuals tend to agree with group consensus. This is true even if the group chooses an obviously incorrect choice, unless another person dissents from the group.
People often choose something unlike what others choose to differentiate themselves, unless that choice is made privately