The strategies are:
1. Social mobility - moving out of social group into another one (legitimate, permeable, stable)
2. Social competition - group challenge/compete with high status group (permeable, unstable, illegitimate)
3. Group creativity - Redefine dimension of comparison & Change
comparative out-group to less successful (impermeable, stable, legitimate)
Tajfel and Turner (1986) - happens due to Individual/social mobility, Social competition, Social creativity