Abstract

Genetic and environmental variation affect all complex human traits and disorders. Recent large-scale genome-wide association studies have been successful in identifying some of the specific genetic variants associated with human behaviour, and we often assume these associations will hold true within the same population irrespective of age or environmental context. However, twin and family studies tell us that for some traits heritability increases throughout childhood and adolescence, a finding reflected at the molecular level by the changing effect sizes of individual genetic variants. In a similar way, exposure to different environments can change how our genetic variants express themselves. One of the major challenges of coming years will be understanding how we can engineer our environment to mitigate genetic risk of disease. But with ever-larger population samples, vast and increasing quantities of genetic data and the need for more detailed environmental exposure information, how can we hope to unravel the complex influences and interactions? I will give two examples of how our lab is addressing that challenge: the spACE project, which is using data from tens of thousands of twins to map the world’s genetic and environmental hotspots (http://bit.ly/tedsgeo), and a new study that is analysing millions of tweets to track genetic and environmental influences on psychological wellbeing in emerging adulthood.