Leach, comparing the book with Robert Ardrey's The Territorial Imperative in The New York Review of Books in 1966, calls On Aggression 'no landmark, but. Fischer argued that Lorenz's view of the instinctive nature of human aggression was 'basically right', commenting that 'Lorenz would probably cite the fury of his critics as further proof of the correctness of his thesis'. Fischer noted that Lorenz acknowledges the role of culture in human life but that he perhaps underrated its effects on individual development. Fischer, reviewing On Aggression in American Anthropologist in 1968, called it a 'fascinating book by a distinguished animal ethologist' that would 'annoy most social and cultural anthropologists' but nonetheless stated 'an important thesis', namely that intraspecific aggression was 'instinctive in man, as it can be shown to be in a number of other species.' Fischer found Lorenz's account of nonhuman animals at the start of the book, written from Lorenz's own experience, 'the most convincing and enlightening'. Thus while the message of inciting in ruddy shelduck and Egyptian geese could be expressed in the words 'Drive him off, thrash him!', in diving ducks it simply means, 'I love you.' In several groups, midway between these two extremes, as for example in the gadwall and widgeon, an intermediate meaning may be found, 'You are my hero.

In the book, Lorenz describes the development of rituals among aggressive behaviors as beginning with a totally utilitarian action, but then evolving to more and more stylized actions, until finally, the action performed may be entirely symbolic and non-utilitarian, now fulfilling a function of communication.

Konrad lorenz theory