Related Experiment Video
Updated: Aug 18, 2026

Cell Lineage Analyses and Gene Function Studies Using Twin-spot MARCM
Published on: March 2, 2017
Growing up and growing apart: a developmental meta-analysis of twin studies
K McCartney1, M J Harris, F Bernieri
1Department of Psychology, University of New Hampshire, Durham 03824.
Abstract:
Developmental change in twin similarity was examined with age contrasts in a meta-analysis of twin studies from 1967 through 1985. Intraclass rs were coded from 103 papers that included data for monozygotic or dizygotic twins, or for both, on personality or intelligence variables. Analyses indicated that there was a general tendency for some intraclass rs to decrease with age. In other words, as twins grow up, they grow apart. There were also developmental differences associated with components of variance for heritability, the shared environment, and the nonshared environment. Mechanisms through which the nonshared environment may operate are discussed.
Related Concept Videos
Case Studies
Longitudinal Research
Behavioral Genetics and Its Designs
The primary methodologies used in behavior genetics include family studies, twin studies, and adoption studies, each providing unique...
Three Developmental Domains
Physical Development
Physical processes, also known as maturation, encompass the biological changes that occur across an individual's life. These changes begin with genetic inheritance and continue through various stages, including growth in height and weight,...
Cognitive Development During Adolescence
Relationship Growth

