Development of tactical deception from 4 to 8 years of age.

One hundred eighteen children, divided into three age groups (4-, 6-, and 8-year-olds) participated in a competitive game designed to explore advances in children's deceptive abilities. Success in the game required children to inhibit useful information or provide misinformation in their communication with an adult opponent. Age trends were evident for all dependent variables, including success at the task, strategic behaviours, and interview data. Four-year-olds were non-strategic and rarely successful, 6-year-olds were increasingly strategic and successful, and 8-year-olds were significantly more subtle in their strategies, more successful at the task, and more likely to verbalize an understanding of their opponent's expectations than younger age groups.

The fate of heritability in the postgenomic era.

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 correlations likely underestimate environmental effects; and G × E interactions are unlikely to be an important aspect of normal development.