Stump the evolutionary psychologist: Remaining puzzles

Excluding a couple of impromptu posts in response to the current events (the Eliot Spitzer scandal and the breakup of Jimmy Kimmel and Sarah Silverman), I have now posted 50 posts in my blog The Scientific Fundamentalist, and this is my fifty-first. I think it’s time to pause briefly and take stock.

In the last 50 posts, I’ve discussed everything from the penis to God and everything in between. Regardless of the particular topic at hand, the consistent theme in my blog has been to illuminate the power of evolutionary psychology to explain human cognition and behavior -- what we think, how we feel, what we want, and what we do. The range of topics covered in this blog reflects my belief, shared by all evolutionary psychologists, that evolutionary psychology provides the best and the most ultimate (as opposed to the proximate) explanations of human behavior.

The fact that evolutionary psychology can explain so much of human behavior, however, does not mean that it can explain everything. Yet. Although I have absolutely no doubt that evolutionary psychology (along with behavior genetics and cognitive neuroscience) can eventually explain all of human cognitions and behavior some day, the day is still far ahead. There is still so much that we do not know.

However, if I may be Rumsfeldian for a moment, not only do we know what we know, but we also know what we don’t know. There is very little that we don’t know we don’t know, and even less that we don’t know we know. The important point is that, unlike social scientists, we know what we don’t know.

In the last chapter of our book Why Beautiful People Have More Daughters, entitled “Stump the evolutionary psychologists: A few tougher questions” (I owe the chapter title to my magnificent editor, Marian Lizzi, at Perigee; my original, highly imaginative idea for the chapter title was “Conclusion”), we discuss some of these remaining questions in evolutionary psychology, what we still don’t know, the known unknowns. We first revisit the six questions that Robert Wright identified as unresolved puzzles in evolutionary psychology at the end of his 1994 book The Moral Animal.

1. What about homosexuals?

2. Why are siblings often so different from one another?

3. Why do people choose to have few or no kids?

4. Why do people commit suicide?

5. Why do people kill their own children?

6. Why do soldiers die for their countries?

In our book we regard the puzzles 1, 2, and 5 as having been resolved since Wright compiled the list in 1994, but the puzzles 3, 4, and 6 as still largely unresolved. We then add a few new items on the list.

7. Why do children love their parents?

8. Why do parents in advanced industrial nations have so few children?

9. Why do people find a tan attractive? Why do men hog the remote control and typically channel surf much more than women? Why are men mostly responsible for barbecuing and carving meats while women do most of the other cooking?

It is important to remember that these are unresolved questions for evolutionary psychology, nothing else. Some questions, like “Why do children love their parents?”, are not even questions for anybody other than evolutionary psychologists. Of course, children love their parents! It’s natural and makes perfect sense! Yes, it makes perfect sense for everybody, except for the genecentric view of the evolutionary psychologists. In order to maximize their inclusive fitness (reproductive success), parents have to love their children to motivate their parental investment into the children, and, as I discuss in an earlier post, how much parents love and invest in a particular child is determined by the likely future reproductive success of the child -- how physically attractive, intelligent, and sociable the child is -- not by how much the child loves the parents. So it is absolutely unnecessary for children to love their parents, because parents will love them even if they didn’t. It is therefore a mystery why children love their parents.

Since I completed the manuscript for our book a few years ago, I have come up with even more puzzles for evolutionary psychology. I will discuss these in the next few post, and will continue to add to the list as I come up with more unresolved puzzles in the coming months and years.