In a group you tend to conform. To not stick out too much. To try to be the same as everyone else.
We hesitate to see what others in the group will do. So we don’t have to make ourselves uncomfortable by being different. It’s the reason people don’t speak up when they see something wrong. That something might just be a typo on a screen during a presentation. That something could be the bullying of someone weaker.
The only thing we can do about this is to find the right group to conform to. Find a group that makes you brave, that’s makes you capable, that empowers you.