We have completed our journey through seven different modelling tools in behavioural and evolutionary ecology. But the obvious question remains … How to choose between them? Could any of the problems have been analysed with any of the methods, or is there a correct choice of a tool in each particular case?

The psychologist Abraham Maslow once quipped ‘If the only tool you have is a hammer, you tend to see every problem as a nail’. There are, indeed, researchers who only use a particular method for anything they see, or perhaps (if the symptoms of the hammer syndrome are less severe) tend to seek out problems that suit a particular method. Sometimes this is because this is the only method they know well: just as when learning a foreign language or a new programming language, everything about modelling tends to get easier when done repeatedly. This can create real ‘developmental inertia’, which makes researchers specialize in one method over others. Reading all the chapters of this book could help to overcome this syndrome to some extent: if, for example, it is clear that fitness is frequency dependent, then a static optimality approach is not sufficient no matter how much one might have grown fond of setting derivatives of simple functions to zero.