Increasingly, researchers and policy makers are realising the importance of exploring the positive aspects of psychology - what makes a flourishing individual rather than what makes people mentally unhealthy. Genetically informed studies, such as those using data from identical and non-identical twins, give us a more comprehensive insight into such behavioural phenomena, allowing us to investigate the origins of individual differences in these traits. Wellbeing has been shown to have a heritability of 36% - that is to say 36% of the variation in wellbeing in a population is due to genetic factors. In this talk, I will give a summary of the work done by the Dynamic Genetics Lab, University of Bristol, on the interplay between genes and the environment in determining an individual's subjective wellbeing. I will also summarise my latest findings on the effect of social comparison on wellbeing in China, which has utilised CFPS data.