We used opportunistic sampling of owners at a pet store in Leth-bridge, Alberta to recruit subjects. We asked the owner(s) if theirdog was well-socialized (i.e., did it have experience of daycare cen-ters or playgroups) and whether they could recall any instances inwhich the dog had been involved in aggression. Dogs with a his-tory of overt fighting were excluded from the study. We obtainedbody weight and height data from the owners. All procedures wereapproved by the University of Lethbridge Animal Welfare Commit-tee.