When prejudice arises from two groups without any other factor being present. 'social categorisation' is the ingroup to which we see ourselves belonging and the outgroup is anyone that is not in the ingroup. 'Social identification' involves the individual adopting their beliefs and values of the groups to which they see themselves belonging. Then 'social comparison' follows, which an individual may boost their self esteem by making comparisons between ingroup and outgroup. This process can lead to group favoritism, prejudice, and stereotyping as people naturally favor those who belong to their own group.