Child height, health and human capital: Evidence using genetic markers

Area of Science:

• Human genetics
• Developmental psychology
• Behavioral science

Background:

• Height is often linked to positive life outcomes.
• The causal relationship between height and these outcomes remains unclear.
• Unobserved factors may confound observational studies.

Purpose of the Study:

• To determine if child/adolescent height causally affects academic performance, IQ, self-esteem, depression, and behavioral problems.
• To differentiate between observational associations and causal effects.
• To explore sex-specific effects of height on various outcomes.

Main Methods:

• Utilized genetic variants as instrumental variables (IV) to address unobserved confounding.
• Employed Ordinary Least Squares (OLS) regression for initial association analysis.
• Examined a comprehensive set of developmental and academic outcomes.

Main Results:

• OLS analysis indicated taller children have higher IQ, better academic performance, and fewer behavioral problems.
• IV analysis showed taller girls, but not boys, exhibit enhanced cognitive performance.
• Contrary to OLS, IV results suggested increased height may lead to more behavioral problems.

Conclusions:

• The association between height and positive outcomes is not entirely causal.
• Height's causal impact varies by outcome and sex.
• Genetic instrumental variable analysis provides crucial insights into complex developmental relationships.