“…The influence of each single definition criterion on the labelling of behaviour as aggressive, and above all on the resulting selection of reactions, is often studied: injury (Shaw and Reitan, 1969;Nesdale, Rule and McAra, 1975), intent (Nickel, 1974;Epstein and Taylor, 1967), and norm deviation (DaGloria and DeRidder, 1977;Ferguson and Rule, 1983;Brown and Tedeschi, 1976;Stapleton, Joseph and Tedeschi, 1978). As far as we know, their combined effect has not yet been systematically tested.…”