Genetic variation influences on the early development of reactive emotions and their regulation by attention.

Introduction: Individual differences in temperament and attention provide an important link between normal and pathological development. Previous studies suggest that during infancy, orienting of attention is associated with higher levels of positive affect and lower levels of negative affect. For older children and adults, self-regulation, as measured by ratings of effortful control, is consistently associated with lower levels of negative affect such as sadness and distress.

Methods: In the current paper we use a longitudinal study of children at ages 6-7 months (Time 1) and 18-20 months (Time 2) to examine how variations in candidate genes relate to emotional and self-regulatory aspects of temperament.

Results: In accord with previous findings, parent ratings of orienting were positively related to positive affect only during infancy. Genetic variation in COMT was related to positive affect at Time l but not Time 2. Negative affect at both Time 1 and Time 2 was related to genetic variation in SNAP25. Genetic variation in CHRNA4 was related to Effortful Control at Time 2.

Conclusions: These findings lend support to the early modulation of emotion by aspects of orienting (Time 1) and executive attention (Time 2), and indicate that emotional reactivity and its regulation are modulated by different genes.