Adaptation demands effective responses to both recurrent and novel environmental challenges. Developmental plasticity and domain-general mechanisms have important consequences with respect to our human capacity for imagining, creating, and adapting to novel environments. They facilitate the evolution of any cognitive mechanism, no matter how opportunistic, flexible, or domain-general, that is able to solve new problems or achieve new goals.

This commentary argues that age changes in heritability are incompatible with Charney's theory. The new genetics must be tempered by the findings that many epigenetic phenomena are random and are linked to pathology, thus making them peripheral to the design of complex adaptations. Behavior-genetic findings are compatible with strong maternal effects; G E interactions are unlikely to be an important aspect of normal development.

An evolutionary model of human behavior should privilege emotions: essential, phylogenetically ancient behaviors that learning and decision making only subserve. Infants and non-mammals lack advanced cognitive powers but still survive. Decision making is only a means to emotional ends, which organize and prioritize behavior. The emotion of pride/shame, or dominance striving, bridges the social and biological sciences via internalization of cultural norms. (Published Online April 27 2007).

Lindquist et al.'s meta-analysis focuses on adult humans; the authors' emotion model might be strengthened by considering research on infants and animals, highlighting the importance of the limbic system. Reliance on the James–Lange theory is questionable; emotions typically occur instantaneously, with dubious dependence on bodily feedback for affect. Stronger evidence for localization might be obtained using more precise emotion terms and alterative localization methods.