Most individual differences in personality, including those that underlie the propensity to rebel, arise within the family. There is a central problem: Why do some scientists, but not others, readily accept radical ideas? Siblings raised together are almost as different in their personalities as people from different families. Sulloway claims that the influence of birth order, like that of gender, can be traced with clear and dramatic consequences. Explores a variety of influences, besides birth order, that affect personality. Considers the role of social influences, especially social attitudes and social class. The family is one of the foremost engines of change.