Effects of social conditions during adolescence on courtship and aggressive behavior are not abolished by adult social experience

Abstract

Social experience during adolescence has long-lasting consequences for adult social behavior in many species. In zebra finches, individuals reared in pairs during adolescence start to court females faster, sing more courtship motifs to females and are more aggressive compared with group-reared males. We investigated whether such differences are stable during adulthood or can be abolished by novel social experience after adolescence by giving all birds extensive experience with group life during adulthood. Courtship and aggressiveness increased in all males, but pair-reared males still had a higher motif rate and were more aggressive than group-reared males. Males no longer differed in courtship latency. In addition to the stable treatment differences, individual differences in behavior remained stable over time. Our results show that differences in behavior acquired during adolescence are preserved into adulthood, although adults still change their social behavior. Adolescence can thus be seen as a sensitive period during which social conditions have a lasting effect on adult behavior.

The adaptive shaping of social behavioural phenotypes during adolescence

“…When introduced to a group, the previously pair-housed males spent less time in proximity to group members and lost more weight [38]. Effects of pair-housing in adolescence could not be reversed with extensive adulthood group-living experience [39]. While fitness benefits remain to be determined, these results together with those in guinea pigs suggest that the phenomenon of adolescent shaping of adult social behaviour and strategies may be a common occurrence, but one that has not been widely investigated.…”

Aggression and dominance: an interdisciplinary overview

“…Early rearing conditions have powerful effects on adult aggressive behavior in animals as diverse as humans [18], pigs [19], rodents [20] and birds [21]. Longitudinal studies initiated at birth in humans show that physical aggression is more frequent in early childhood than at any other time during the life-span, and that high levels of aggression in adults often ensue from failure to develop the ability to inhibit aggressive tendencies [18].…”

“…Studies of rodents, humans and other primates show that various types of early adversity, including repeated maternal separation and neglect, strife between parents, post-weaning social isolation and peri-pubertal stress, can each independently induce the development of deviant forms of adult aggression, including mismatches between provocation and response, attacks on inappropriate targets, and deficits in social signaling. In rodents, primates and zebra finches, both post-natal and adolescent phases of development represent sensitive periods during which social conditions have lasting effects on adult aggression [20,21]. Interestingly, spontaneous aggression can even be elicited in robots "raised" under adverse environmental conditions [22].…”

Effects of the social environment during adolescence on the development of social behaviour, hormones and morphology in male zebra finches (Taeniopygia guttata)

“…If aggression of pair-reared males depends on social density, this may explain why we found low aggression when testing males in dyads. In previous studies, pair-reared males were also more aggressive than group-reared males when later tested in dyads [ 99 ], but this may have been a consequence of winner-loser effects during the first tests.…”