PhD Glenn Geher

Too! many!! exclamation!!! points!!!!

That was my very first real thought about this book, reached after just a few paragraphs. An exclamation point tells the reader that This Is Big! Time to Pause and Think It Over! Using too many both impedes the flow of the narrative and gives readers false cues. It is quite grating. The hyper-abundance of the first few sections eventually settles down to mere over-abundance, but the problem never goes away. Which is too bad, because -- if read without interruptions -- this is a really interesting book.

That's not to say that it's a perfect book. It misses two major points -- both of which seem to be commonly missed by evolutionary psychologists. (Which is all the more surprising because I figured them out for myself -- surely, if I can do it, they can!) (Yes, I know, I used an exclamation point.)

The first problem -- or, rather, the last, in book order -- is the discussion of mental health issues and why mental health problems exist (pp. 157-159). Author Geher's explanations are clearly hand-waving to try to explain away something that he hasn't figured out. But the answer is really quite clear, if we look at a lot of disorders in detail. It's the sickle cell phenomenon.

To explain: sickle cell anemia is a condition which occurs when a person has two copies of a defective gene for blood cells. A person with sickle cell anemia is likely to die of it, and will certainly be very debilitated. Evolutionary logic says that those defective genes should have bred themselves out of the population. But they're still there. Why? Because a person who has only one sickle cell gene, rather than two, is much more resistant to malaria than a person who has no sickle cell genes. In Africa, where malaria has been endemic for many, many generations, the sickle cell gene flourishes, because it's better to lose one child in four to sickle-cell than to have everyone suffer malaria.

And so with mental disorders. A person with autism is very badly handicapped, socially. (I know; I have autism.) But many of the geniuses of history have shown clear signs of autism. Similarly, bipolar disorder is dangerous and a leading cause of suicide and accident. But people with bipolar disorder are often our most creative, original thinkers. It has been shown that many genes which contribute to autism also contribute to intelligence; I suspect that many genes which contribute to bipolar also contribute to creativity. So: there are people who have too many of those genes, or the wrong combinations, and they get autism, or bipolar, or whatever, without the corresponding benefits. But enough people get genius-type autism, or genius-type bipolar, that the genes survive and flourish -- those genes are an overall benefit, not cost, to the community. Humans have evolved very quickly, and those genes are probably responsible. In time, we may get autistic genius without autistic difficulties, and bipolar creativity without bipolar mood swings -- but often evolution produces an imperfect answer before, or instead of, a perfect one. And we need to keep in mind that evolution keeps happening.

Second, the book discusses multi-level selection without discussing multi-purpose selection. For example, it talks about how we reward people who are brilliant musicians, or poets, or dancers, or whatnot -- people with those traits are chosen by other people as preferred sexual partners, and they do well reproductively. But this ignores why the music or poetry or whatever benefits the community. There is good reason to think that music and dance and the like hold the community together, and a cohesive community is more productive than one that is not cohesive. So the whole community survives well, and that makes the creative traits desirable -- and so the community rewards them reproductively. To treat these traits as improving an individual's fitness without looking at how they affect the relatives and neighbors of the person who has them -- the person's inclusive fitness -- is certain to distort the evolutionary analysis.

Oh, and the book treats ovulation as if there are only two types: unconcealed (as in animals that go into heat) or concealed (in which a female does not know if she is fertile, and her potential mates don't, either). It has long been thought that humans have concealed ovulation, and the book argues that, in fact, people know when women are ovulating. There is some evidence that that is true. But this sort of misses the point. People sort of know. But only sort of. Human women have, one might say, "plausible deniability" ovulation. It's not either-or.

Those are big objections -- sez I, anyway. And they are too common in this field. So you won't learn everything about evolutionary psychology from this book.

That said, you're likely to learn a lot. Almost all of it controversial. E.g. the basic, fundamental, biological reasons why men typically are more aggressive and jealous than women. Why it's so hard to end wars. Why we're so concerned about justice -- at least for ourselves: we don't like cheating. Why parenting is so difficult. Why we're (sort of) monogamous (but not quite). You may not like it. But you'll be wiser for knowing it. And that's the highest achievement we could ask of any book.

If you want, you can put an exclamation point after that last sentence.

[Addendum 1/12/2018 -- added "and why mental health problems exist" to clarify the fourth paragraph.]… (mehr)