The adaptive calibration model (ACM) is an evolutionary-developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern…

The current study tested sex-specific pathways to early puberty, sexual debut, and sexual risk taking, as specified by an integrated evolutionary-developmental model of adolescent sexual development and behavior. In a prospective study of 238 adolescents (n = 129 girls and n = 109 boys) followed from approximately 12-18 years of age, we tested for…

Responds to Maccoby's and Hinde's commentaries on the Belsky, et al. article in this issue. Highlights several points of concurrence and disagreement. Draws attention to the potential benefits of asking questions about proximal and ultimate causation simultaneously and, thus, the need for child developmentalists to think about both the how and why…

Comments on Belsky, Steinberg, and Draper's article in this issue. Discusses the claim for a connection of stressful childhood environments and early pubertal maturation. Argues that early puberty need not imply a shift from a "quality" toward a "quantity" reproductive strategy and that nonevolutionary factors can account for…

The stress response systems of the human child are highly sensitive to social challenges. Because stress hormones can have negative developmental and health consequences, this presents an evolutionary paradox: Why would natural selection have favored mechanisms that elevate stress hormone levels in response to psychosocial stimuli? Two…