Genetic and environmental continuity in personality development: a meta-analysis

Area of Science:

• Behavioral Genetics
• Developmental Psychology
• Personality Science

Background:

• Personality traits show increasing longitudinal stability from childhood to adulthood.
• Explanations for this trend involve intrinsic maturation versus socializing influences.
• Behavioral genetic studies can disentangle genetic and environmental contributions to personality stability.

Purpose of the Study:

• To investigate the extent to which genetic and environmental factors contribute to the increasing stability of personality across the lifespan.
• To evaluate age trends in heritability, environmentality, and the stability of genetic and environmental influences on personality.
• To determine the primary mechanisms driving the increase in personality trait stability over development.

Main Methods:

• Meta-analysis of effect sizes from 24 longitudinal behavioral genetic studies.
• Inclusion of 21,057 sibling pairs across a wide age range (infancy to old age).
• Application of linear and nonlinear meta-analytic regression models to analyze age trends.

Main Results:

• Both genetic and environmental influences on personality increase in stability with age.
• Genetic contributions to phenotypic stability are moderate and constant, offset by decreasing heritability in childhood.
• Environmental contributions to phenotypic stability increase significantly from childhood to adulthood.

Conclusions:

• The increasing longitudinal stability of personality across the lifespan is predominantly driven by environmental mechanisms.
• Environmental factors play a progressively larger role in maintaining personality consistency with age.
• Understanding the interplay of genetic and environmental stability is crucial for explaining personality development.