• mortality
• social capital
• social epidemiology
• psychosocial factors

Among nations with high wealth and development, all-cause mortality rates are the highest in the USA. This excessive mortality is evident for both men and women, and for all age groups except for the oldest old.1 Public health experts increasingly recognise that this remarkable failure is much more than a matter of patchy healthcare coverage, growing socioeconomic disadvantage and changing ethnic composition.1 Although these characteristics undoubtedly set the USA apart from its peers, other facets of society are also important for people’s health in the USA. It is widely accepted that social relationships influence health and longevity2; and among US adults, generalised trust recently reached its lowest level since 1972.3 Highly dependent on the social context, generalised trust is markedly lower in the USA than in many European countries.3 Trust—the belief that the sincerity, benevolence or truthfulness of others can be depended on4—is an indicator of social cohesion. Social cohesion reflects the psychosocial environment2 and is expressed by trust, altruism, reciprocity, norms and values that are shared between members of a community.5 Markers of social cohesion (including trust) have been associated with better physical and mental health outcomes, including mortality according to various studies.2 5 6 As US adults die sooner on the one hand, and experience lower levels of generalised trust on the other—relative to counterparts in similarly developed countries, an investigation …