Playful defensive responses in adult male rats depend on the status of the unfamiliar opponent
Article first published online: 12 FEB 1999
Copyright © 1999 Wiley-Liss, Inc.
Volume 25, Issue 2, pages 141–152, 1999
How to Cite
Smith, L.K., Fantella, S.-L.N. and Pellis, S.M. (1999), Playful defensive responses in adult male rats depend on the status of the unfamiliar opponent. Aggr. Behav., 25: 141–152. doi: 10.1002/(SICI)1098-2337(1999)25:2<141::AID-AB6>3.0.CO;2-S
- Issue published online: 12 FEB 1999
- Article first published online: 12 FEB 1999
- Manuscript Accepted: 16 MAR 1998
- Manuscript Received: 29 MAY 1997
- The Natural Sciences and Engineering Research Council of Canada
- play fighting;
- social testing;
- Rattus norvegicus
Adult male rats reared as pairmates from weaning were tested in a neutral arena with both members of another pair (one at a time). The unfamiliar pairs were found to engage in play fighting, although they were more likely to escalate the encounter into serious fighting than were pairs of familiar rats. Based on their within-home pair behavior, each pairmate was designated as a dominant or a subordinate. When the test encounters between unfamiliar males were analyzed with regard to whether the pairings consisted of two dominants, two subordinates, or a mixed pair, the pattern of play fighting was found to be attenuated. Both dominants and subordinates were more likely to initiate playful encounters, to respond defensively during these encounters, and to do so using adult-typical tactics of defense when paired with an unfamiliar rat that was dominant in its home cage. The mechanisms by which the home status of unfamiliar male rats can be identified by another male are discussed, particularly with regard to the role that play fighting may serve for this function. It is concluded that the data support the hypothesis that play fighting can be used by adult rats for social testing, which in this case seems to involve ascertaining the opponent's fighting capability. Aggr. Behav. 25:141–152, 1999. © 1999 Wiley-Liss, Inc.