Heiner Mühlmann What is showing-off? Showing-off is display behaviour. An example: Somebody gives a beggar alms and knows that a famous lady is watching him doing it. He was intending to give the beggar something anyway. Suddenly he realizes that the lady is watching him. He notices his behaviour changing and that he cannot help showing-off. A communication system with two channels is the result. The ?rst channel is the objective channel the only concern of which is that of the giver and the receiver of alms. The second channel is the display channel and it is here that the scene is transm- ted to the onlooker. I have borrowed the term 'display' from zoology, or to be more exact, ethology where it means 'behaviour altered by evolution which transmits information'. The great-crested grebe for - ample gathers nesting material with his bill and rises vertically in the water in front of the female. He has no intention of bui- ing a nest at this time. He is performing a nesting display with the message that he is ready to pair.