Cinderella men

I think this is the first time I've seen evolutionary biology featured in a Press piece on crime. The piece notes the disproportionate number of children in New Zealand killed by step-fathers.

Why stepfathers kill their lovers' small children but spare their own has troubled Canadian evolutionary psychologist Martin Daly for decades.

He and his late wife Margo Wilson founded the Cinderella theory in the 1980s, researching the deaths of 700 Canadian children.

What they found suggested the unconditional love a parent feels for a screaming child who has soiled their nappy, is not innate for a stepparent - and makes them more likely to lash out.

... Building on Darwin's theory of evolution, the relationship between the new man on the scene and his lover's child is forged by biological altruism, Daly and Wilson found.

That means humans, like other animals, are programmed to investing their time into reproducing their own genes - not someone else's - and sometimes that resentment becomes deadly.

..."My argument, in psychology - and it's the same with those other animals who engage in step-parenting - is the step-parent is doing it as a courting step.

"People love their own children more than they love someone else's child. That's not to say they don't love them... [but] generally, they're not going to throw themselves in front of a truck for them."

In the Canadian research, birth parents overwhelmingly smothered or shot their children, and a third of fathers committed murder-suicide.

Stepfathers usually beat children to death and just 1 in 67 killed themselves too, Daly and Wilson found.

They note that the New Zealand data for a proper test would be hard to come by (as is all NZ data about everything because of because).

Satoshi Kanazawa explained it this way:

In retrospect, this makes perfect sense. Parental love for children is evolutionarily conditional on the children’s ability to increase the parents’ reproductive success. Stepchildren do not carry any of the genes of the stepparents, so there is absolutely no evolutionary reason for stepparents to love, care for and invest in their stepchildren. Worse yet, any resources invested in stepchildren take away from investment that the stepparents could make in their own genetic children. So, in the cold, heartless calculus of evolutionary logic, it makes perfect sense for the stepfather to kill his stepchildren, so that his mate (the mother of the stepchildren) will only invest in their joint children, children whom the stepfather has had with the mother and who carry his genes. Only they can increase the stepfather’s reproductive success.

But he also cites some contrary evidence from Sweden suggesting that the background characteristics of stepdads do a lot of the work.

In their paper, Temrin et al. do not question that stepchildren are more likely to be killed and maimed by their stepfathers; they only question discriminative parental solicitude as the explanation for it. They point out, and empirically demonstrate with a small Swedish sample, that men who become stepfathers, by marrying women who already have children from previous unions with other men, are more likely to be criminal and violent to begin with. And Temrin et al. argue that their greater tendency toward criminality and violence, not their genetic unrelatedness, is the reason they are more likely to kill and injure their stepchildren.

Once again, in retrospect, this makes perfect sense. Divorced women with children are on average older, so they have lower mate value than younger women without children. Given choice, and all else equal, all men would prefer to marry younger women without children rather than older women with children with other men. The logic of assortative mating would suggest that women with lower mate value are more likely to mate with men with lower mate value. And, as I explain in an earlier post, men with lower mate value are more likely to be criminal and violent.

So a proper New Zealand study would want to correct for the stepfathers' ex ante characteristics. It would also then partially answer Jan Pryor's question of the theory, raised in the original Press piece:

The theory also did not explain whether solo-mothers living financially strained lifestyles were targeted by men who preyed upon them and their children, Pryor said.

I'm curious how much of the effect here works through the biological Cinderella story and how much works through the assortative mating dynamics at the lower tail of the distribution.

Add to the list of "open questions that could be answered by somebody with time to muck around in IDI applications and the Stats Data Lab", or "Masters theses waiting to be written".

Academic pile-ons

Whatever you think about the quality of Satoshi Kanazawa's academic work, the folks who signed the open letter to The Times' Higher Ed damning his work sure chose the wrong time to do it if they had other than malicious intent.

To recap, Kanazawa's academic work has been subject to critique for some time. I've found a lot of his work awfully fun, and I've enjoyed his pieces on IQ and beauty. I've not gone through them with a referee's fine-toothed comb. And Satoshi could have done himself a lot of favours by answering critics more directly than he has.

But the current furore started with a blog post, as noted here. The post could have been wrong; further analysis of an updated version of the data that Kanazawa used suggested the effects went away if the fourth wave's data were included. That kind of thing happens in blog post analyses. That's why bloggers put up speculative trial balloons as blog posts - it helps to sort out where we might be getting things wrong before we go in full bore.

Kanazawa's post launched a populist campaign for his firing from LSE. On principle, even folks who disagree with Kanazawa's published work really ought to circle the wagons against this kind of populist pressure. I disagree with a lot of published work, as loyal readers might have noticed. Suppose that one of the folks at Otago Public Health - the NZ folks with whose published work I most frequently disagree - got into trouble over a blog post that got folks riled up. Suppose that, against all odds, there were mass public outrage against one of the neoprohibitionists' calls for bans on alcohol and lots of folks wanted the guy fired from his academic position. I'd hope I'd not I'd pick that moment as being the right time to launch a big public campaign against the guy's academic work. It's just not on. I'd hope instead to be writing posts in defense of academic freedom. And once the furore died down, I'd go back to putting the boot in. You shouldn't lose your job for being wrong in a blog post, and you shouldn't ride public anger fueled by same.

And so I signed an opposing letter in The Times Higher Ed in defense of Kanazawa. If it makes some folks happy to call me a racist for having done so, I've got a thick enough skin for it. Anybody who knows me, whether personally or as loyal readers, knows better. It makes me a bit sad that folks are happy to read racism into my post defending sweatshops, as I reckon the biggest force behind the anti-sweatshop movement is protectionist buy-American unions whose pro-natalism is necessarily racist in practice. Honi soit qui mal y pense.

Kanazawa [updated]

I've been a fan of Satoshi Kanazawa; I've long had regrets that I didn't know he was at Canterbury for the couple of months we overlapped there.

Not entirely unsurprisingly, he's gone and annoyed some folks. This time it's looking serious. The Add Health data series interviews high schoolers in three waves, making a nice panel data set. One question asks the interviewer to rate the respondent's attractiveness on a five point scale. Satoshi ran some regressions on attractiveness and found racial differences in means after correcting for possible confounds like weight; black women, but not men, were found less attractive in the surveys. He then speculated about whether testosterone levels might account for the result. His blog post, as usual, was pretty blunt about what he'd found; it's mirrored here as it's now been pulled.

The pile-on has been pretty brutal. He's been called a racist for finding data suggesting black women are less attractive than white or asian women; I'm not sure whether he's a racist also for finding data suggesting that there are no big racial differences in attractiveness among men.

Here's Huffington calling him a racist.

Lindsay Beyerstein is less than charitable in her interpretation of Kanazawa's stats. She gets the last wave of Add Health data and says that the difference disappears by Wave Four, raising troubling questions about Kanazawa's bias. I'd say rather more likely, he just had the first three waves' data sitting on his hard drive; getting the fourth wave would have been a pain in the arse for a blog post, so he just used the data at hand.

Hank Campbell is no more generous, with lots of snarky scare quotes about what factor analysis is. Because three interviewers rated respondent attractiveness at different points in time, you need to draw some summary stat out of the three observation. I'd have just gone with a straight average, maybe weighted towards the latter waves when the respondents were older. Kanazawa ran a factor analysis instead. The difference between the two isn't going to be great - factor analysis will try to extract some common underlying measure from the three observations, making the weights across waves endogenous. But Campbell likes to say 'factor analysis' with the scare quotes to make it seem dodgy.

The first thing I'd thought when I saw the controversy was that OK Cupid recently put up data noting that black women get far fewer messages from other OK Cupid members than they ought to; this was potentially consistent with Kanazawa's story (or with other equally plausible ones). But Campbell calls Hontas Farmer a racist for citing that data.

Now, Huliq reports Kanazawa's lost his blog slot at Psychology Today (one wonders how long Walter Block will last).

Scientific American wonders whether Add Health should be collecting data on interviewer-rated attractiveness:

I am disturbed by the fact that the Add Health study's adult researchers even answered the question of how attractive they rated these youth.

Never mind that a ton of research on kids' social capital would draw on measured attractiveness as a potential explanatory variable; apparently it's better to make things unknowable than to risk disturbing findings.

The Daily Mail insinuates that Kanazawa's a racist for his prior work suggesting IQ might be responsible for some poor health outcomes in Africa, and cites an LSE colleague calling for his firing.

It is not the first time that Dr Kanazawa, 48, a lecturer within the department of management at the LSE, has been accused of peddling racist theories.
In 2006 he published a paper suggesting the poor health of some sub-Saharan Africans is the result of low IQ, not poverty.
Professor Paul Gilroy, a sociology lecturer at the LSE, said: ‘Kanazawa’s persistent provocations raise the issue of whether he can do his job effectively in a multi-ethnic, diverse and international institution.
‘If he announces that he thinks sub-Saharan Africans are less intelligent than other people, what happens when they arrive in his classroom?’
He added: ‘The LSE risks disrepute if it fails to take a view of these problems.’

Here's Linda Gottfredson on IQ and health; here's Garrett Jones on IQ and economic outcomes.

Britton at Scientific American, linked above, raises a lot of better questions about whether Kanazawa's findings would stand up to more thorough investigation; so does Robert Kurzban. But it was a freaking blog post! Blog posts are where you put up initial data exploration and speculation to bat things around and see whether it's worth more thorough investigation. If you disagree with the analysis on a blog post, you write up your own post on why you think it was wrong or how it could be done better (like Kurzban); calling for Kanazawa's firing borders on witch hunt.

The LSE beclowns itself if it sanctions Kanazawa for this particular blog post.

I take more seriously Andrew Gelman's critique of Kanazawa's published work. It's fine to be wrong; it's a bit worrying that Kanazawa posted subsequently on that study without noting or addressing the critique (I'll take Gelman's word on this). [See below] As for how much weight I'd put on the soon to be released open letter of a bunch of psychologists castigating Kanazawa, well, I'd want to know what kind of Sneetches they are.

Michael Mills's "Seven Things Satoshi Kanazawa Cannot Blog About" is a must read...

Update: I've read Gelman's critique in more depth. Gelman's an excellent statistician. But some of the criticisms there lodged would apply to a reasonably high proportion of published empirical work. Endogeneity issues are everywhere; damning everyone who's ever had potential endogeneity / reverse causality problems in their published work would be a bit broad. And failing to adjust significance tests for the potential number of comparisons (as a guard against data mining) - I have a hard time thinking of many published pieces that have done that other than the metastudies that say we can't trust any empirical work.

Gelman's specific (and not at all unreasonable) worry on datamining is that Kanazawa's work on whether more attractive couples have more daughters tests whether the most attractive couples have more daughters than all others; equally plausible would be tests of whether the least attractive couples had the fewest daughters, the top two categories of attractive couples against the rest, and so on. XKCD summarized the problem here. But subsequent work with a different data set found the same result; matching the prior paper's result via datamining would then have taken mining across different datasets until finding the one that gave the best match, and I'm not sure there are all that many datasets that include attractiveness data.

Finally, Gelman (2007) critiques Kanazawa's earlier (2005) work for missing that there are potential problems in using number of daughters on the right hand side of a regression equation and number of sons on the right if some couples use a stopping rule that aims at particular ratios. But Kanazawa's 2007 piece recognizes that issue. I'm not sure whether the prior pieces' results were sensitive to this specification issue, but I'm also not sure it's right to say, as Gelman implies, that Kanazawa then went on to do other work without taking due account of critics' view of prior work.

Fundamental rights

Kanazawa today hits on a very Hansonian point: why do we care about some kinds of inequalities but not others? Bottom line from an ev bio perspective is the "right" to have kids. But some folks are stuck without a willing partner.

In the United States, millions of people – mostly, young, poor men, the same people who don’t have health insurance or choose not to take advantage of the available health care – are left mateless, sexless, and childless, and are destined to die as total reproductive losers. In every human society, there are more childless men than childless women.

How come nobody cares that millions of people in the United States fail to achieve the ultimate goal of all biological existence, the meaning of life itself? Why isn’t it the government’s job to make sure that every American has sex regularly and frequently and produces children? Why doesn’t the government import surplus women from Russia and Ukraine and distribute them at taxpayers’ expense to millions of young, poor men who can’t otherwise get laid?

Back in September, Hanson wrote:

Yet other “insensitive” categories are associated with huge inequalities, which few folks seem interested in talking about, much less considering how policy might influence. There is no social pressure whatsoever against maligning these groups. Especially striking are inequalities in attractiveness as a friend, lover, etc. not mediated by sensitive categories. These factors include physical appearance, vigor, charisma, personality, height, etc. Folks are well aware such inequalities exist, but have little concern about them, and no interest in policies to reduce them.

An especially striking example is inequality among men in their ability to attract women as lovers. If you don’t like “alpha/beta” labels, then call it what you will, but there are consistent correlations among men in this regard, which are consistently correlated with insensitive categories. While this inequality has large consequences for utility and happiness, there is no interest in reducing it, and people feel quite comfortable insulting these type of “losers”.

The second welfare theorem works for money endowment, but I have a hard time seeing how it could work for these other kinds of inequalities, or at least how it could work without insanely high deadweight costs.

Kanazawa on Tiger

I read Satoshi Kanazawa on Tiger Woods, and I cry a little that I never got the chance to have a beer with him during the three months that we overlapped at Canterbury (I didn't know he was here, and I was just settling in). When the staff club re-opens after Christmas, I will again kick Simon Kemp from the Psych department in the shins for letting Kanazawa go.

Bill Clinton became the President of the United States, unconsciously, indirectly, and ultimately, so that he could get laid. David Letterman became America’s favorite entertainer, unconsciously, indirectly, and ultimately, so that he could get laid. Tiger Woods became the most successful golfer in history, unconsciously, indirectly, and ultimately, so that he could get laid. It would be a tremendous evolutionary puzzle if these men, after spending their entire lives attaining the status and resources they attained, then didn’t have affairs. And their wives married them because they were the kind of men would could cheat on them.

Scientists are not in the business of making predictions for the future, at least not for the short run and not at the individual level, and, if they were, in the realm of human behavior, they would be wrong most of the time. But here’s a prediction that I can safely make for the year 2010.

During the course of the year 2010, there will be at least one sex scandal involving a notable politician, there will be at least one sex scandal involving a notable athlete, and there will be at least one sex scandal involving other celebrities. And the politicians, athletes, and celebrities involved will all be men.

Yes, this is the most banal prediction that anyone can make. (I also predict that there will be lots of snow in Buffalo, NY, this winter.) But do me a favor: If you are going to complain that my prediction is banal, which it is, then please don’t act surprised when it comes true, which it inevitably will. A statement cannot simultaneously be banal and surprising (let alone outrageous and disappointing) at the same time.

If, on the other hand, I turn out to be wrong in my prediction, I will hang up my hat as an evolutionary psychologist, and, after the last of the monkeys fly out of my ass, become a social constructionist feminist. Get back to me in January 2011.

I like folks who have confidence in their predictions and are willing to put things on the line.

Smart deviants

GNXP discusses a Richwine piece in The American on relative intelligence of liberals and conservatives. Richwine nicely tips the hat to Charlton's "Clever sillies" hypothesis but suggests rather that IQ will correlate with making a choice one way or the other about the default position we're endowed with, whether ideology, religion, or anything else. Intelligence will then show a correlation with atheism, if only because only folks from the upper tail of the distribution decide to think about it rather than just stick with the default.

This is of course also Satoshi Kanazawa's hypothesis: high IQ will disproportionately select for evolutionarily novel values and preferences. I had great fun spending a couple weeks on evolutionary psychology and political preferences in my graduate public choice class this year. Some fascinating work out there.