Transgenerational effects of childhood conditions on third generation health and education outcomes

- Undernutrition around age 9 affects grandchildren along sex-specific lines.
- In each case, exposure leads to better mental health in the 3rd generation.
- The underlying mechanisms appear to be biological rather than social.
- The findings possibly reflect epigenetic modifications of the gametes.

This paper examines the extent to which pre-puberty nutritional conditions in one generation affect productivity-related outcomes in later generations. Recent findings from the biological literature suggest that the so-called slow growth period around age 9 is a sensitive period for male germ cell development. We build on this evidence and investigate whether undernutrition at those ages transmits to children and grandchildren. Our findings indicate that third generation males (females) tend to have higher mental health scores if their paternal grandfather (maternal grandmother) was exposed to a famine during the slow growth period. These effects appear to reflect biological responses to adaptive expectations about scarcity in the environment, and as such they can be seen as an economic correctional mechanism in evolution, with marked socio-economic implications for the offspring.