We are the Social Biobehavioural Research Group at University College London, a World Health Organization Collaborating Centre. We investigate how social connections and behaviours impact people’s health. By conducting cutting-edge, cross disciplinary research, our aim is to determine how our health is influenced by both social ‘assets’ and ‘deficits’. These include social relationships, arts and culture, leisure, nature, and social prescribing (assets), as well as loneliness, isolation, and social restrictions (deficits). We investigate how these factors affect individual and population health, the underlying ingredients and mechanisms, and how these effects vary across society. This then advances understanding of how policies and practice might evolve to improve population health.