Behavior Genetics History IQ

Erasmus Darwin without Francis Galton

Erasmus Darwin is an interesting character. R.A. Fisher thought highly of him. But claiming that he invented a rocket engine on the basis of a vague, un-captioned doodle in his commonplace book is unwise. Desmond King-Hele has made a lot of far-fetched claims of that kind. They will backfire, like rockets do. Or injure the occupant, as that unstable bathchair carriage invented by the good physician did and crippled him for life.

As the editors of this collection The Genius of Erasmus Darwin (2005) note, Erasmus had a famous grandson, Charles Robert Darwin, the naturalist. That one. On reading this I was struck: did he not have some other famous grandson? Hmm.

Why yes, he did. Francis Galton! Who was rather more like Erasmus than Charles was, since he was a polymath too, and particularly shared his grandfather’s interests in machinery and instruments. He was also responsible for having a plaque erected to Erasmus at Lichfield.

But Francis had rather different ideas about heredity. Erasmus believed that one’s state of mind during copulation affected the characteristics of the offspring. The ultimate soft-heredity. De Candolle believed that too. It is a rich source for humour, and a good measure.

So I flipped to the index to look for Galton. Surely one of the other contributors to this collection would have mentioned him? The only Galton mentioned is one of Erasmus’s patients, Samuel, Francis’ other grandfather. Oh and Mary Anne too: Samuel’s daughter and Frank’s aunt. But no Frank!

Odd. So I turn to the scanned copy at google books and search that. This turns up a ref to a letter to Lucy Galton, Frank’s grandmother and a patient of Erasmus, not in the index. Still no Frank. So this is getting very weird.

The book has 24 chapters by all sorts of different people. I chose one of these chapters, which is about heredity. It mentions all sorts of things, including eugenics, but not Francis Galton, who coined the very word and is Erasmus’ Grandson! It mentions C.B. Davenport, a Francis Galton disciple, and all sorts of people connected, but no Frank. Zip.

So this is like one of those movies in which the subject has a car accident and wakes up with some key element of history removed, to his utter confusion. Everyone he talks to gives him a blank stare when he mentions the erased person. Like that weak one about The Beatles.

One should certainly never attribute to artifice that which can be explained by stupidity and ignorance, and both of those are in full evidence in this collection. So we must ask: was this a deliberate editorial intervention? Or just plain stupidity and ignorance?

Accidental omission 24 times in a row and omission from all the directly relevant chapters, concerned with subjects Francis Galton contributed heavily to, cannot be plausible. Many key papers, letters etc. about Erasmus are in the Galton Papers at UCL. I have handled them there myself. Deliberate erasure then.

The collection is from a conference to celebrate the 200th anniversary of the death of Erasmus Darwin, apparently held in 2002. The book was published in 2005. I doubt if many have read it, since it is ridiculously overpriced.

Next, the new edition of the Great Soviet Encyclopedia, with scissors.

I wrote more about Galton’s advocacy of his grandfather over at Ideas Sleep Furiously.

Breadsall Priory, last home and very brief of Erasmus Darwin. Visited often by Frank as a boy, when his grandmother lived there.
Behavior Genetics Eugenics IQ

Eugenic Taint

There is no more tired or trite argument than that some or other topic is tainted by association with eugenics. For instance, research into intelligence or behavior genetics in general. These aim to describe the world as it is rather than as it ought to be. Eugenics is a policy which attempts to alter the world, to fashion how it ought to be (did you need to be told that?) It was connected to genetics in much the same way that hygiene (a policy) was and is connected to medicine, which is why eugenics was described as “racial hygiene”. However you can describe the world without trying to change it, even if that logical distinction has been clouded by the “social justice” activism enthralling university campuses.

This argument can go to breathtakingly ludicrous lengths, as in the idea that “frequentist” statistics is somehow tainted by the great statistician R. A. Fisher, who happened to be a staunch eugenicist at the same time. (It is worth pausing over the depressing fact that contemporary academics feel compelled to keep a straight face while discussing childish arguments, instead of simply laughing them out of the room.) As the entire scientific establishment before 1939 was in favour of eugenics as a policy, the scope is more or less unlimited for detecting, or not detecting, the eugenic taint anywhere the fancy of the witch-sniffer directs. Any field is a candidate. The mediocrities churned out by the academic-research complex must pursue politics over science to make a living in the fields of pretense. Here the unwholesome process led to statistics and Ronald Aylmer Fisher.

RA Fisher, statistician and eugenicist

The essential idea here has been reused many times in bad science fiction movies, as in The Hands of Orlac (1924). The celebrated pianist Orlac loses both hands in an accident and has new hands grafted on. But they are the hands of a murderer! Aaaargh! Chop off those frequentist hands! They are the hands of a eugenicist!

The Hands of Orlac
The Hands of Orlac!

Behavior Genetics IQ Statistics

Experts Weigh In

Experts are not always helpful, especially when they are experts on other topics. Richard Hamming, inventor of Hamming Codes, has ideas about intelligence:

We will now take up an example where a definition still bothers us, namely IQ. It is as circular as you could wish. A test is made up which is supposed to measure “intelligence”, it is revised to make it as consistent internally as we can, and then it is declared, when calibrated by a simple method, to measure “intelligence” which is now normally distributed (via the calibration curve).All definitions should be inspected, not only when first proposed, but much later when you see how they are going to enter into the conclusions drawn. To what extent were the definitions framed as they were to get the desired result? How often were the definitions framed under one condition and are now being applied under quite different conditions? All too often these are true! … Brains are nice to have, but many people who seem not to have great IQs have done great things.

The Art of Doing Science and Engineering (1997)

When you spend many years at Bell Labs, sharing an office with Claude Shannon while he invents Information Theory, it is not surprising that restriction of range prevents you from appreciating deficits in ability.

IQ pioneers have wrestled long and hard with the definitions they employ, a history Hamming seems not to be aware of. Not only were they competent statisticians, they invented many of the techniques commonly used today. Galton coined the term “Normal Distribution” and invented regression and correlation techniques for bivariate normal variables, Karl Pearson generalized them to (most) distributions, Cyril Burt and Charles Spearman invented Factor Analysis, and so on.

The assumption of normality has strong support from the Central Limit Theorem once you realize that IQ is polygenic, and is in any case merely convenient. Contrary to Hamming’s suspicion, no important facts depend on the assumption of normality. IQ will not be more or less heritable if you change the distribution to one with fatter or thinner tails, or skew it. If you are prepared to lose efficiency and think it is worth your while you can instead use non-parametric methods like the bootstrap. People have not done that because it would gain them next to nothing of importance, not because they do not understand the issues. See for example the long discussion about normality by Arthur Jensen in Bias in Mental Testing (1980). As he points out the assumption of normality is almost certainly false, as it usually is in other fields, but modest departures from normality like slightly fatter left tails (due to harmful mutations) are not worth losing sleep over.

Wading in, boots and all, to other fields is not necessarily a bad idea for statisticians and other experts. It may even be helpful. See for example David Bartholomew’s helpful Measuring Intelligence (2004). But usually it backfires, as in the case of Bernie Devlin et al Intelligence, Genes, and Success: Scientists Respond to The Bell Curve (1997). They would help behavior geneticists figure out bread-and-butter ideas like heritability. Instead they triumphantly produce a slightly lower estimate of narrow-sense heritability (0.39) by front-loading their sample of twins with adolescents. Heritability increases with age, see Plomin et al Behavior Genetics (2017). Far from improving the techniques used, Devlin et al shed darkness where there was light.