Psychology 9-1 GCSE - 

5.1.1 - Know the terms:

a) Obedience - 

A form of social influence where an individual acts in response to a direct order from another person, who is usually an authority figure. 

b) Conformity - 

A type of social influence involving a change in belief or behavior in order to fit in with a group. 

c) Deindividuation - 

The phenomenon of people losing self awareness, restraint and responsibility for their actions when in a group. In a sense people will do things in a group they would otherwise not have done individually. 

d) Bystander effect - 

Also called bystander apathy. Refers to the tendency of people to take no action in an emergency situation when there are others present.