Positive affectivity is a trait that reflects stable individual differences in positive emotional experience; high levels of the trait are marked by frequent feelings of cheerfulness, enthusiasm, and energy. Positive affectivity is relatively independent from negative affectivity, as these traits developed in response to different evolutionary pressures. Similar to personality traits, trait affect is structured hierarchically. Although there is not a clear consensus regarding the lower-order components of positive affectivity, we emphasize a model that includes components of Joviality, Self-Assurance, and Attentiveness. Different measures of positive affectivity are reviewed, as well as relations to overlapping constructs such as extraversion, happiness, and subjective well-being.
In terms of its biological bases, positive affectivity is moderately heritable and is linked to left prefrontal brain activation, likely mediated by the dopaminergic system. There are few demographic or environmental factors that are systematically related to levels of positive affectivity; for instance, the trait does not differ according to age or gender. However, frequency of social activity and identification as religious/spiritual are both positively correlated with positive affectivity.
Positive affect is relevant to a number of important domains. For example, low levels of positive affectivity are characteristic of numerous psychological disorders (particularly depression). Current marital and job satisfaction can be predicted based on previous measurement of positive affectivity. Positive affectivity is also related to better physical health, such as increased resistance to infectious illnesses. Finally, although mean levels of positive affectivity do not appear to differ greatly across cultures, there is evidence that culture may influence cross-situational stability and perceptions of trait affect. We conclude by showing that although temperament is an important factor in determining levels of positive affectivity, individuals are still free to take action to increase their happiness in lasting ways.