In the century and a half since Charles Darwin’s publication of the Origin of Species, evolutionary theory has become the bedrock of modern biology. Attempts to apply the theory of evolution to cognition, however, have not fared as well. Darwin himself thought that there was no fundamental cognitive difference between man and the ‘higher mammals’. Many researchers still hold that common descent implies cognitive closeness. This view has excused anthropomorphism and often led to an overinterpretation of data from experiments with non-human primates. Recent studies on the cognitive capabilities of birds suggest that evolutionary convergence may be the rule rather than the exception in animal cognition. For instance, crows have been found to be much better in the use of tools than monkeys. Also, it has become clear that songbirds are far better models for the study of the brain mechanisms of human speech and language than apes. A prominent attempt to apply evolutionary and functional considerations to brain and cognition is that of neuroecology. According to neuroecology, differences between classes of individuals (e.g. between males and females) in the mechanisms of brain and cognition are the result of adaptive specialisation. For instance, male songbirds often have larger brain nuclei involved in song than their female counterparts, because males learn to sing songs and females don’t. However, sex differences in brain size also exist in duetting songbird species where both sexes sing equally often and they both learn their songs. The new discipline of evolutionary psychology is based on the mistaken view that evolution can explain how the human mind works. A prominent claim by evolutionary psychologists is that men and women behave and think fundamentally differently, a result of sex differences that were supposed to have been functional in the Stone Age. This suggestion is based on empirical research and on received wisdom in evolutionary biology and behavioural ecology. The empirical data are often overinterpreted. In addition, recently it has been shown that the conventional sex roles that animals were thought to have may not be an adequate rendition of how animals actually behave.