The individual in the crowd
In this final chapter, we draw together the threads of evolution, causation, development and phylogeny that have run through this book and show how they underlie one of the most striking features of animal lives – their tendency to be social. Tinbergen's four questions have stood the test of time, they are as important as they ever were and as he did in his pioneering book, The Study of Instinct (1951), we shall attempt a synthesis involving them all. Our knowledge of animal behaviour has grown enormously since Tinbergen's time and has spawned whole new disciplines such as behavioural ecology and neuroethology, but there is still much be gained by asking his different kinds of questions about behaviour. Asking how (causally) animals choose their mates, for example, is hugely illuminated by understanding why (in an evolutionary sense) they choose the mates they do, and vice versa. Since virtually all animals are social for at least part of their lives, social behaviour provides an obvious base for a synthesis of many aspects of behaviour across a wide range of species.
When we observe flocks of birds, swarms of insects or herds of antelope, it is easy to lose sight of the individual in the crowd. If a group stays together, it is because individual animals all benefit from staying with one another.