• hair cortisol;
  • development;
  • social challenge;
  • Macaca radiata;
  • aggression;
  • affiliation;
  • risk;
  • early environment;
  • early adversity;
  • maternal relationship;
  • perinatal stress


Social challenges during the perinatal period influence the mother–infant relationship in nonhuman primates and may affect the offspring's response to later social challenge(s). Relocation of a breeding colony of monkeys (Macaca radiata) created two groups of infants: one group experienced social group relocation to a new housing facility during the perinatal period (ATYPICAL) and the second group developed within a constant environment (TYPICAL). At a mean age of 25 months, all animals were removed from their natal group and placed in same sex adolescent social groups. Behavioral observations were collected after group formation or introduction to a new group. ATYPICAL subjects showed increased aggression and reduced affiliation compared to TYPICAL subjects. Hair cortisol in male subjects collected 6 months after introduction was elevated in the ATYPICAL subjects compared to TYPICAL subjects. These findings demonstrate that early life challenges affect behavior as well as stress hormone responses to social challenge in adolescence. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 316–322, 2013