What about the size of the group?
Do you feel more pressure to conform when the group is large than when the group is small?
This issue was studied in a classic experiment nicknamed the "Gawkers" study.
In this study, the experimenters instructed groups of accomplices to stand in an area of high pedestrian traffic
and simply look upward (staring at a 6th floor window) without talking or pointing.
The experimenters then filmed the hundreds of passing pedestrians and counted the number of passers-by who looked up.
By varying the size of the group of accomplices (the groups had 1, 2, 3, 5, 10, or 15 people in them)
the experimenters were able to study the effect of group size on pressure to conform.