Development of a Scale Measuring Genetic Variation Related to Expressive Control

ABSTRACT It has been theorized that a substantial genetic component underlies the Self-Monitoring Scale. The identity of this component, however, is not yet known. In order to identify and better understand it, a more precise measure of the component is required. The present research attempted to ( a ) identify an axis of the self-monitoring two-factor space with maximum genetic variance; and ( b ) bootstrap a scale more highly correlated with this genetic maximum than is the Self-Monitoring Scale using twins. Evaluation of the new scale against criteria of validity indicates that scale construction was reasonably successful. The new measure had a cross-validated monozygotic twin intraclass correlation of .76 and a dizygotic twin intraclass correlation of .16. This work yields a new research tool and suggests a new approach to personality assessment. Correlates of the new measure as well as theoretical and methodological issues relevant to the measurement of a latent genetic entity are discussed     

The evolution of human mating: trade-offs and strategic pluralism

During human evolutionary history, there were "trade-offs" between expending time and energy on child-rearing and mating, so both men and women evolved conditional mating strategies guided by cues signaling the circumstances. Many short-term matings might be successful for some men; others might try to find and keep a single mate, investing their effort in rearing her offspring. Recent evidence suggests that men with features signaling genetic benefits to offspring should be preferred by women as short-term mates, but there are trade-offs between a mate's genetic fitness and his willingness to help in child-rearing. It is these circumstances and the cues that signal them that underlie the variation in short- and long-term mating strategies between and within the sexes.     

What makes responses prepotent for young children? Insights from the grass–snow task

Understanding how responses become prepotent is essential for understanding when inhibitory control is needed in everyday behaviour. We investigated prepotency in the grass–snow task—in which a child points to a green card when the experimenter says ‘snow’ and a white card when the experimenter says ‘grass’. Experiment 1 (n=48, mean age=3.5 years) investigated the response method effect—whether pointing is prepotent because it is habitual. Experiment 2 (n=60, mean age=3.5 years) investigated the response set effect—whether responses are prepotent because the child plans to make them in the task. Experiment 2 also provided evidence that children could remember the rules in the task. Experiment 3 (n=30, mean age=3.4 years) produced further evidence that children could remember these rules. We found no evidence for the response method and response set effects, suggesting that prepotency in the grass–snow task is more ‘stimulus‐driven’ than in tasks previously studied. The implications of our findings are discussed in relation to other developmental inhibitory tasks and to children's reliance on inhibitory control to regulate their everyday behaviour. Copyright © 2008 John Wiley & Sons, Ltd.