Table 1.
The four aggression items and 20 behavioral items included in the questionnaire.
Table 2.
Factor analysis of behavioral items using 14 breeds (n = 4922).
Figure 1.
Cluster analysis on scores of four types of aggression in 14 dog breeds.
Cluster analysis with Ward's method was conducted on aggression scores of 14 breeds. A1–4 is aggression toward owner, child, stranger, and dog, respectively. Degree of aggression scores are shown in color spectrum (from white to blue). Tree diagram is drawn with distance scale. Symbols ahead of breed names represent the groups when the number of clusters is set to three.
Figure 2.
Cluster analysis on points of five temperamental factors in 14 dog breeds.
Cluster analysis with Ward's method was conducted on temperament factor points of 14 breeds. F1–5 is “sociability with humans,” “fear of sounds,” “chase proneness,” “reactivity to stimuli,” and “avoidance of aversive events,” respectively. Degree of aggression points are shown in color spectrum (from white to green). Tree diagram is drawn with distance scale. Symbols ahead of breed names represent the groups when the number of clusters is set to three.
Table 3.
Multiple regression analysis on owner-directed aggression.
Table 4.
Multiple regression analysis on child-directed aggression.
Table 5.
Multiple regression analysis on stranger-directed aggression.
Table 6.
Multiple regression analysis on dog-directed aggression.
Figure 3.
The associations between temperamental factors appearing in daily life and aggression in 14 dog breeds.
Multiple regression analyses in each breed revealed associations between five temperamental factors and four types of aggression. The width of arrows and numbers show the number of breeds in which a temperamental factor was significantly associated with a type of aggression.