Ritualization
In the book, Lorenz describes the development of rituals among aggressive behaviors as beginning with a totally utilitarian action, but then progressing to more and more stylized actions, until finally, the action performed may be entirely symbolic and non-utilitarian, now fulfilling a function of communication. In Lorenz's words,
"Thus, while the message of inciting in Ruddy Shelduck and Egyptian Geese could be described as "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 the Widgeon, an intermediate meaning may be found: "You are my hero. I rely on you." (Page 64)
Read more about this topic: On Aggression