Examining the etiological associations among higher-order temperament dimensions

• The common etiology among PA, NA, and EC was examined in a sample of twins.
• There were common genetic and nonshared environment influences across PA, NA, and EC.
• There were shared environmental influences in common to NA and EC.
• There were significant and unique genetic influences for PA and NA.
• There were significant and unique shared environmental influences for PA.

A multivariate independent pathway model was used to examine the shared and unique genetic and environmental influences of Positive Affect (PA), Negative Affect (NA), and effortful control (EC) in a sample of 686 twin pairs (M age = 10.07, SD = 1.74). There were common genetic influences and nonshared environmental influences shared across all three temperament dimensions and shared environmental influences in common to NA and EC. There were also significant independent genetic influences unique to PA and NA and significant independent shared environmental influences unique to PA. This study demonstrates that there are genetic and environmental influences that affect the covariance among temperament dimensions as well as unique genetic and environmental influences that influence the dimensions independently.