Nature , Nurture , and Individual Change

Determining the degree to which persistent human behaviors and traits are the result of genetics or environment is important for a host of theoretical reasons in psychology. This article asks whether the results of such determinations are relevant to the practical tasks of individual change as attempted, for example, through therapy, parenting techniques, or self-transformation. Examples from the psychological literature on happiness or “subjective well-being” illustrate the common idea that a trait being largely genetic implies that it is more difficult to modify than one that is largely environmental. The most widely known theoretical approach to disentangling genetic from environmental effects in humans is behavioral genetics, with its central concept of heritability (h). This article argues that measures of h do not predict the ease or difficulty of modifying behaviors or traits of individuals. A concept different from h, that of innateness, is explicated, but it, too, is found not to be a useful predictor of individual modifiability. The general conclusion is that knowing only the degree to which a human characteristic results from nature or nurture has no implications for the ease or difficulty of altering that trait.