title: The monkey puzzle: a systematic review of studies of stress, social hierarchies, and heart disease in monkeys.
abstract: BACKGROUND
  It is often suggested that psychosocial factors, such as stress, or one's social position, may play an important role in producing social gradients in human disease. Evidence in favour of this model of health inequalities has relied, in part, on studies of the health effects of the natural social hierarchies found among non-human primates. This study aimed to assess the strength of this evidence.
  
  
  RESULTS
  A systematic review was carried out to identify all studies of psychosocial factors and coronary artery disease (CAD) in non-human primates. We searched databases (MEDLINE, PsycInfo, EMBASE, and Primatelit from inception to November 2010) to identify experimental and observational studies of the impact of social reorganisation, social instability, and disruption of dominance hierarchies on primate CAD outcomes. We also handsearched bibliographies and examined the citations to those studies in public health articles. Fourteen studies were found which presented evidence on CAD and social status and/or psychosocial stress. These suggested that the association between social status and disease may be sex-specific: in female monkeys dominant status may be protective, with subordinate females having a greater extent of atherosclerosis. In male monkeys the reverse may be the case.
  
  
  CONCLUSIONS
  Overall, non-human primate studies present only limited evidence for an association between social status and CAD, Despite this, there is selective citation of individual non-human primate studies in reviews and commentaries relating to human disease aetiology. Such generalisation of data from monkey studies to human societies does not appear warranted.
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, United Kingdom. mark.petticrew@lshtm.ac.uk
authors.forename: Mark
authors.initials: M
authors.lastname: Petticrew
authors.forename: George
authors.initials: G
authors.lastname: Davey Smith
mesh_terms: D000818:Animals; D003324:Coronary Artery Disease / Q000209:etiology*; D016208:Databases, Factual; D005260:Female; D000882:Haplorhini; D006801:Humans; D008297:Male; D008992:Monkey Diseases; D012919:Social Behavior; D013315:Stress, Psychological