size of the majority
presence of a partner
size of discrepancy between opinions
dissimilarity and social distance
economic competition
scapegoating
conformity to social norms
media stereotypes
proximity
similarity
self-disclosure (trust)
physical attractiveness (average=beautiful, beautiful=unapproachable)
empty love (commitment)
infatuation (passion)
romantic love/passionate love (intimacy and passion)
companionate love (commitment and intimacy)
consummate love (commitment, intimacy, and passion)