This book is about the way in which the evolution of birds and mammals is affected by social learning and by the traditions formed by social learning. From observation and experiment, we know that higher animals can acquire information from or through the behaviour of others, and through their own behaviour they can transmit this information to the next generation. Variations in such socially acquired and transmitted behaviour-influencing information cannot be under direct genetic control, since animals with very similar genes can have, and pass on, very different behaviours and traditions. There is clearly another inheritance system, a behavioural system of information transmission, which is superimposed on the genetic system. Some years ago we decided that the evolutionary consequences of this additional tier of variation and inheritance were worth exploring, and set out to see how our view of the evolution of higher animals is altered by incorporating non-genetic behavioural inheritance and the traditions that it produces. This book is the outcome of that endeavour.

We found that adding the behavioural system of information transmission has some radical implications for the current gene-centred view of evolution. For example, the classical distinctions between development and evolution become very blurred. An animal tradition is the product of a historical, evolutionary process, yet it can be formed and transmitted only if it is actively constructed during the behavioural development of individuals and groups.