Middle-class family sizes across the globe have been declining. Women are having children later, and are having less of them or none at all. In economist Bryan Caplan's view, this is mostly because prospective parents have been caught up in the view that their potential children are `blank slates' - they will underperform or turn to the bad side unless parents invest huge amounts of their own precious time in launching them on an optimal life-trajectory. No wonder kids are such a poor investment!
This view is, however, almost entirely false. The life prospects of your children, their intelligence, personalities and even potential criminality are outside your control, consequences almost exclusively of their genes. If you're from good stock, then almost certainly your kids will turn out all right, whether you over-invest in them or not.
In a field full of diverse opinions underpinned by a library of popular books, it's important to state what's different about Caplan's entry into this crowded field. Quite simply, it's based on real empirical evidence and research (which we technically call `science'). The way to separate the effects of on-board genes and family-upbringing is to look at twins, especially those separated at birth and raised by different families. The other piece of the puzzle is provided by the fate of adopted children, where the child's outcome can be compared with the traits of the birth-parents and also with the adopting family.
What does all this tell us? The genes win hands down. Chapter 2 is the main meat in this book, reviewing numerous `behavioral genetics' studies with the following results:
1. Parenting has little to no effect on overall lifetime health of offspring. Parents don't affect height, weight or teeth-quality.
2. Mozart in the womb or no Mozart, parenting has zero long-term effect on a child's intelligence as measured by IQ tests (the gold standard). Separated twins correlate almost perfectly with each other; adopted children correlate with their birth parents.
3. Exactly similar conclusions hold for: life happiness, success in life, educational attainment, character, values, sexual attitudes and religion.
The only area where nurture seems to matter is whether your children will appreciate you later in life: it pays to be nice to them.
Why do so many parents believe otherwise? Their evenings are spent working over the homework and sponsoring life-enrichment classes for their little ones; weekends involve chauffeuring their offspring to sports matches or dancing classes; summers bring improving camps, while piano lessons occupy any remaining time.
The answer is that families, like the army, are a total environment with asymmetry of power. You can control the experiences of your little one and so you do, whether what you offer conforms to your child's likes and aptitudes or not. For a period you can force a child to go against its genes but be forewarned, it will not stick.
Chapter 3 re-iterates some of the points in chapter 2 and rebuts charges of `genetic determinism': we are not zombies controlled by a genetic `program'. Since the consequences of genes are so powerful, however, Caplan suggests that you `choose a spouse who resembles the kids you want to have': assortative mating implies you probably did, but if you applied this level of rationality to your romantic engagements you're probably in trouble anyway. Surprisingly, Caplan argues that `if you want to dramatically improve a child's life, adopt from the third world'. Good for the child perhaps, but did Caplan really review the solid, scientific work on ethnic differences in IQ and personality?
Chapter four shows, with statistics, that children are a lot safer today than they were in the 1950s (which themselves were a golden age as compared to 1900). The difference is almost entirely due to the fact we have largely conquered childhood diseases. Parents tend to worry more about abduction, kidnap and murder and these have, if anything, gone up but the actual rates seen by middle-class families are vanishingly small.
The rest of the book is devoted to arguments as to why having more children is good both for you and for the world. Briefly, your kids will enrich your old age even if they are a pain in the short term; and large populations sustain and nurture culture and the new ideas which drive progress. I agree with both these ideas but they're hardly earth-shaking or new.
One curious section in chapter 5 (p. 116) explores the reasons why - as a matter of fact - middle-class people are choosing to have fewer children today. After rejecting the standard economic argument (diminishing marginal returns to extra children) he comes up with three reasons: changes in values, self-imposed rules and changes in foresight. This comes down to the decline in religion, the time-consuming urge to over-parent and an alleged civilization of our basic urges.
I have never heard of a flimsier and less convincing set of reasons. The elephant in the room is the pill: contraception which is universally used and which doesn't impact the pleasures of intimacy (unlike the condom). So having children is now solely a conscious decision for any woman with enough `foresight' to take the pill. No wonder something with such a negative short-term impact on finances, career and recreation tends to be put off. Not so hard, is it?
So this book is a mish-mash of solid science, common-sense and Bryan Caplan's unsubstantiated opinions mixed in with too much information (Caplan wears shorts to work in the winter). Even at 184 pages it feels padded and it must be said that Caplan is not a good writer. He adopts the slightly folksy, informal style which most populist academics seem to like but his writing is dry, unstructured and far too repetitive. Caplan should have followed economist Steven Levitt (of `Freakonomics' fame) in signing up a real writer (like Stephen Dubner) to add the anecdotes and sparkle which keeps the reader glued to the page.
Caplan's previous book, `The Myth of the Rational Voter' was similarly overly-dry but that was targeted at his fellow economists and had a sizeable dragon to slay (the theory of Rational Ignorance). Here he's aiming at the general public: the arguments are fine but it could have been a far, far better book - the result is that it won't have the impact it deserves, something to bear in mind for the second, improved and expanded edition, Dr Caplan.