Evolutionary life history theory addresses how organisms, including humans, vary in the allocation of resources to growth, survival and reproduction across the life course. Life history strategies are defined by key decisions that trade off finite resources against competing demands to achieve reproductive goals. Both across and within species, the trade-off between the allocation of resources to growth and to reproductive efforts results in organisms employing varying strategies that can be characterised, loosely, as ‘slow’ or ‘fast’. A ‘slow’ life history strategy is characterized by later maturity and proportionally greater investment of resources in a smaller number of offspring. In contrast, a ‘fast’ life history strategy involves more effort directed towards reproduction, such as earlier puberty and sexual activity. Consequently, adolescent behaviours of unprotected sex and earlier pregnancy, as well as violence, law breaking and substance abuse, can be seen as central components of a fast strategy in which the future is discounted relative to the present amd competition for mates is crucial. Although such behaviours may increase fitness on average, they include costs for some individuals, especially in modern society.

Developmental cues for life history strategies appear to be particularly important during the ages of 0-5 years and research has therefore focused on effects of adversity during this period. Finding show that increasing adversity is associated with fast strategies.

It is clear that research into individual differences of life history strategies is highly important, increasing understanding of risky behaviour and informing interventions. I aim to use causal analysis from genetic epidemiology (e.g. MR and negative controls) and theoretical insights from evolutionary models to combine knowledge of ‘how’ exposures lead to certain outcomes with an understanding of ‘why’ these relationships may exist.