Environmental risk and the evolutionary psychology of teenage motherhood
| Principal Investigator: | Sarah E. Johns |
|---|---|
| Project dates: | 1999-2003 and ongoing |
| Funding: | Philip Mary Morris Scholarship & NHS (Gloucester) |
| Partners: | Gloucestershire Health Authority |
A number of factors are correlated with teenage motherhood. However, the underlying causes of young pregnancy and birth remain elusive. This project investigated the contention that teenage motherhood is the result of an evolved reproductive strategy that allows for variation in life history event timings, and that having children at an earlier age may promote lineage survival when the environment is unstable and risky, and personal future is uncertain. The psychological mechanism of time perspective, or how an individual’s future decisions are made in light of their past experiences, is proposed as the link between environment and behaviour in this context.
Data were collected by postal questionnaire, using a retrospective case-control study design. Within Gloucestershire, every woman who gave birth for the first time between January 1997 and December 2000 whilst a teenager was contacted, as were a randomly selected equal number of women who gave birth while aged 20 to 27. These women were asked to complete a detailed questionnaire, and of the 1782 questionnaires posted, over 45% were completed and returned.
Teenage mothers were found to subscribe to a different life history trajectory— they had intercourse at a younger age, and expected to complete their families and die earlier—when compared to the older mothers. Additionally, women who perceived their pre-conception neighbourhood environments as being dangerous, or reported that their family life was disrupted during the transition to adolescence, had increased odds of being teenage mothers. An individual’s perceived level of risk and danger therefore appeared to be important in reproductive decision-making. A time perspective based on negative past experiences was also found to be a partial mediator between environmental risk and teenage motherhood. Together, these results suggest that past environments can affect future outlook and, in consequence, reproductive timing.
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