Investments made in early childhood last a lifetime, and the earlier in life, the greater the return, according to James Heckman who was awarded a Nobel Prize for economics. Conversely, shocks to child development also can last a lifetime. For example, children who were young at the time of the 1984 famine in Ethiopia are 5cm shorter at adulthood, have lower education and are more likely to have recently been ill.
When assessing long-term effects of early life circumstances, it's difficult to disentangle biological from social processes. An outstanding question is: why can't children catch up after shocks to their development?
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