Parent-Child Warmth:

David C. Geary:

"Parent-child warmth ... may vary in ways that prepare children for adult life. ... K. MacDonald proposed that the degree of parental warmth modifies the neurobiological systems that underlie affective reactions to social dynamics, much like early language exposure modifies aspects of the language system. These modifications result in children becoming more or less sensitive to other people, influencing the extent to which their behavior is relatively self-serving or cooperative. Harsh treatment ... may 'shut down' the systems that generate the feelings that facilitate empathy and social cooperation, resulting in a relatively self-serving social style. As with many traits, cost-benefit trade-offs associated with a relatively cooperative or self-serving approach to social relationships depend on context and cannot be known ahead of time."