Data from the Carolina Abecedarian Project (N = 104) was used to test the hypothesis that infants deemed at-risk who received an intensive and individualized intervention would develop a slower life history (LH) strategy as measured in young adulthood. Additionally, it was predicted that this effect on life history strategy would mediate several effects of the intervention. This possibility was tested in the areas of risk-taking, mental health, and cognitive ability. Results supported the hypothesis that the intervention caused a slowing of LH strategy and that LH strategy mediated the effect of the intervention on risk-taking, mental health, and cognitive ability. Lastly, it was predicted that any effects would be strongest at the most molar level of measurement. This was found for a composite trait and cognitive ability, but not for risk-taking and mental health. The results have several significant implications, but given the small sample size, replication is especially important. (author abstract)