The propensity to take risks is highly variable between individuals. Individuals who suffer stressful experiences early in life tend to show faster physiological development, an effect known as ‘psychosocial age acceleration’. Evolutionary theories predict that individuals who experience accelerated ageing are more likely to become risk-takers, as their likelihood of morbidity and mortality later in life is increased, and they therefore have less to lose and more to gain by taking risks. This predicts a ‘pace-of-life’ syndrome in which individuals exposed to early stress adopt a “live fast, die young” attitude, whereas those under less stress are more risk averse (Ellis et al. 2009; DOI: 10.1007/s12110-009-9063-7). Alternatively, the causality could be reversed – increased risk-taking could increase stress, and thereby accelerate ageing. As of yet, there are hardly any tests of these predictions in humans, and none that investigate causality. In this project, we will test whether groups of people who have inherited different genetic variants for epigenetic age acceleration differ in their risk-taking behaviour; or, conversely, whether those who have inherited different genetic variants for risk-taking behaviour differ in epigenetic markers of ageing.