I want to write a long post about how impressive and detailed Melvin Konner’s The Evolution of Childhood is, but to do so I would have to read it at least a couple times more and delve deeply into the bibliography. It ranks with The Evolutionary Biology of Human Female Sexuality by Randy Thornhill and Steven Gangestad in terms of its thoroughness and the density of its information. The Evolution of Childhood discusses, among other things:

• how the environment shapes childhood
• how group behaviors work
• how group dynamics work
• how life in evolutionary times differs from the present
• problems with the Freudian interpretation of childhood
• sexual play or expression among children is common (“Contrary to some claims of cultural historians, anthropologists find that liberal premarital sex mores are not new for a large proportion of the cultures of the ethnological record and that liberal sexual mores and even active sexual lives among adolescents do not necessarily produce pregnancies. In fact, a great many cultures permit or at least tolerate sex play in childhood (Frayser 1994)”).
• why parent-child conflict is effectively inherent in the relationship

I lack the time to discuss what Konner says about each topic; here’s an example of the subtlety of his thinking:

Most explanations of behavior occur at one level only. But as pointed out by Tinbergen (1963), the question ‘Why did the animal do that?’ can be answered at different levels, four of which were immediately identified in his classic paper: phylogenic, ecological, developmental, and eliciting. These can be exemplified by categories of answers to a question about a short flight of a bird—say, a jay rising from a holly bush up to a longleaf pine. It flies because it is a bird; because flight gave it an advantage […] in its environment of evolutionary adaptedness; because its ontogeny gave it light bones, wings, feathers, and a motor neuron circuit oscillator for flight, through a genetically determined maturation pattern shaped by nutrition, exercise, and practice; and because a fox is chasing it.

This goes on to his own development of how the “causation” behind any given behavior might work. Arguments about the root causes of behavior often boil down to people arguing at different levels:

Levels 1 – 3: Remote or Evolutionary Causation

• 1. Phylogenetic constraints: “Because an organism of a certain broad taxonomic type, it is constrained to some extent in the way it can solve the problems posed by its environment [. . .]”
• 2. Ecological/demographic causes
• 3. Genome

Levels 4 – 6: Intermediate or Developmental causation

• 4. Embryonic/maturation process
• 5. Formative early-environment effects
• 6. Ongoing environments: “These are factors such as nutrition, stress, and reinforcement contingencies [. . .]”

Levels 7 – 9

• 7. Longer-term physiology: “Though mainly hormonal, longer-term physiology also accounts for other metabolic effects [. . .]”
• 8. Short-term physiology.
• 9. Elicitors or releasers: “The immediate external causes of behavior, elicitors are the events in the stimulus envelope that precipitate the behavior; ethologists call this the releasing mechanism, and to the learning psychologist it is the conditions or unconditioned stimulus.”

I’d never consciously realized how levels like this work before. And I’d never consciously realized many of the subtle arguments Konner makes. The Evolution of Childhood is almost oppressively thorough; the woman I’m dating mentioned that I complain about books that are long magazine articles or that gloss their topics, and in doing so she implied that I should be thankful for The Evolution of Childhood’s move in the opposite direction. But I also came to the end, with the 100+ pages of citations, and felt that I’d come a long way since I began. Very few books feel like an intellectual journey in the most positive sense of the word. This one does.