The stability of self-control across childhood

• We examined the stability of self-control in children over 5 years.
• We analyzed the source of variation in self-control with a twin sample.
• Results indicate two stable classes for both the twin and analytical samples.
• Results indicate that variation in self-control is predominantly genetic.

While the link between low self-control and several behavioral and social problems is widely supported, debate remains regarding the stability of and the genetic and environmental sources of variation in self-control. Using data from the Early Childhood Longitudinal Study, Kindergarten Class 1998–1999 restricted data set, a sample of 360 twins was compared to a sample of 423 non-twins in order to examine the stability in self-control. The twin sample was also used to examine the genetic and environmental sources of stability in self-control. Findings indicated two stable classes for both the twin and singleton samples, and substantial stability in average self-control from kindergarten through fifth grade in both samples. The ACE decomposition model indicated strong genetic contributions to self-control (76%) with the remaining variation attributed to non-shared environment. Overall, the data suggest that self-control is identifiable early in life, stable across childhood, increasingly influenced by genes, and thus, is a critical focus for early intervention.