He applied the “Page 99 Test” to his new book, The Evolution of Childhood: Relationships, Emotion, Mind, and reported the following:
Page 99 of The Evolution of Childhood is fairly typical of the book, and it illustrates the general approach of the book while raising some specific themes. The first paragraph uses Darwinian evolution to explain how the brains of monkeys and apes evolved to reflect complexities in social behavior. When comparing different species, there is a correlation between brain size and the size of social groups, and this is probably due to the need to remember all the actors, how important they are, what they can do to or for you, and also to interpret their facial and vocal expressions, which become much more complex as we go from mammals generally to monkeys, from monkeys to apes, and from apes to humans. The complexity of the brain is hard-wired (genetically coded), as is the variety of facial and vocal expressions, but for any given individual growing up in any group, a huge amount of learning goes into becoming a socially competent adult. The basic brain circuits and the basic communications may be hard-wired, but the context and meaning of the communications is largely learned.Learn more about The Evolution of Childhood at the Harvard University Press website and Melvin Konner's blog.
The page goes on to mention the work of Robert Seyfarth and Dorothy Cheney, which showed that African vervet monkeys have unexpectedly complex calls, three of which signal the approach of three different kinds of enemies—snakes, leopards, and hawks. The three require different responses, and the young learn those responses as they grow and imitate others.
Page 99 also describes the insightful work of Harold and Sarah Gouzoules, who showed that monkeys called pigtail macaques have different screams for different kinds of aggression among themselves, depending on who is attacking whom and how badly. These different screams are interpreted differently by relatives, who respond accordingly. “Moreover, there is a developmental course: as juveniles grow to adulthood, their agonistic screams become more situation-specific… The remarkable fact is that monkey calls have fine shades of meaning and a component learned during socialization, despite being in some ways innate.”
Finally, Page 99 says that play is essential to the development of the young in all monkeys, apes, and us, and that it stimulates brain growth as well as forming the foundation for social relationships. As with my book as a whole, this page shows how much our non-human relatives can teach us about the evolutionary background to human childhood, how evolution has made many things innate, but also how it has relied heavily on things that have to be learned as the young grow slowly toward adulthood.
It has been wisely said that nothing in biology makes sense except in the light of evolution. My book shows that nothing in childhood does either. It is the product of a lifetime of work and thought, and its goal is to change the way we think about children and childhood, placing our views on a more scientific and biological foundation.