ABSTRACT
The evolution of care eliciting could only advance if, at the same time, complementary adaptations were taking place in the targets of care elicitation (e.g. parents). In this sense, evolution is dependent on a co-ordination of change in CNS structures which are complementary within an interaction (MacLean 1985; Price 1988). This form of interactional evolution is rather more complex than say, evolution of specific characteristics (form, colour, shape, etc.), which (when passed on) result in advantage. The same principles of natural selection apply, but in this case it is not just individual characteristics that gain an advantage but rather the complementary interaction between individuals. In other words, natural selection operates directly on a relationship in which the goal of each is different (the care elicitor to gain from and the care giver to give to). Hence, because the interaction is selected, poor elicitors can be compensated by good providers and, to a lesser degree, vice versa.
