Heritability estimates of somatotype components based upon familial data

Area of Science:

• Human genetics
• Anthropometry
• Behavioral genetics

Background:

• Somatotype, a system for classifying human physique, includes endomorphy, mesomorphy, and ectomorphy.
• Understanding the genetic and environmental contributions to somatotype is crucial for fields like sports science and public health.

Purpose of the Study:

• To estimate the heritability of endomorphy, mesomorphy, and ectomorphy in a French-Canadian population.
• To differentiate between genetic and common familial environmental influences on somatotype components.

Main Methods:

• Anthropometric assessment of somatotype components (endomorphy, mesomorphy, ectomorphy) using the Health and Carter system.
• Analysis of sibling and parent-child pairs from 239 French-Canadian families.
• Statistical control for socioeconomic indicators to estimate residual familial correlations.

Main Results:

• Sibling correlations for endomorphy, mesomorphy, and ectomorphy were 0.40, 0.30, and 0.38, respectively.
• Broad heritability estimates (HB) after controlling for familial environment were 0.50 (endomorphy), 0.42 (mesomorphy), and 0.54 (ectomorphy).
• Narrow heritability (HN) for ectomorphy was estimated at approximately 0.36, including assortative mating effects.

Conclusions:

• Somatotype components exhibit significant heritability, indicating a substantial genetic influence on body types.
• Common familial environment plays a role, but genetic factors are primary determinants of somatotype.
• Ectomorphy shows a notable heritability, influenced by both genetics and assortative mating.