Chapter 28 INTERPERSONAL RELATIONSHIPS Introduction and overview (p. 428) Affiliation: the need for other people (p. 428) Love and intimacy (p. 428) Relationships: definitions and varieties (p. 429) Voluntary/involuntary relationships (p. 429) Arranged marriages (p. 430) Gay and lesbian relationships (p. 430) ‘Electronic’ friendships (p. 431) Different types of love (p. 431) The power of love (p. 431) Is romantic love unique to western culture? (p. 431) An evolutionary theory of