Lampl bases his thesis upon a paper by Konrad Lorenz called 'Der Kumpan in der Umwelt des Vogels' ('The Rôle of the Companion in Bird Life') and quotes copious examples from it to show the parallels which exist between human and bird behaviour, such as the parent bird's instinct to feed the inmates of its nest whether they are its own offspring

or not; the permanent fixation of young birds to their earliest object regardless of its species; 'marriages' between birds of the same sex; the taking over by the female bird, in certain circumstances, of the male bird's function of building the nest; signs of feelings of loss on the part of a bird if his or her partner suddenly dies or disappears, and of joy if he or she re-appears; imitative actions; a sense of racial purity; and numerous other strange instances of a similar kind.