In Groups: One that we belong to and feel some loyalty toward like a high school, clique, racial group, ethnic group, family or organization which you work for. Dominant group.
Out Groups: Groups that we don't belong to and may feel some antagonism toward because they are different. Cliques you don't belong too, racial groups, the opposite gender, other tribes, religious, competitive companies.
Reference Groups: the groups we compare ourselves to. Help us understand our position in society. Use to determine how to act- family, musicians, athletes.