Monday 4 April 2016

Boiling off the non-believers: Henry Harpending, RIP

Henry Harpending has died. He was best known for two brilliant publications with Greg Cochran: the 2005 paper “The natural history of Ashkenazi intelligence” and the 2010 book “The 10,000 year explosion: How civilization accelerated human evolution”. Both had a common theme: given selection, groups could evolve in different ways, according to what they required or valued in human nature. Henry was a gentleman who was not browbeaten by the social and political pressures of the academic world, who thought clearly, followed insights to a logical conclusions, and who did all this with great civility.

In October 2014 ago he offered me the chance to comment on a first draft of his paper “Plain and Simple: On a Novel Feature of Amish Personality”. He proposed that those who did not fit in with the particular Amish lifestyle were “boiled off” in that they left the community, leaving the true believers to become more like themselves, a process I likened to making a consommé. He was typically kind about my efforts, saying that he agreed the Amish were probably being bred for civility. He said “Civility is not a bad gloss for what they are being bred for. Greg always points out that every society selects for something where that “something” is a direction in a high dimension space. Of course our press has recently butchered Nicholas Wade for pointing out just that in his recent book. ”

Looking at the post I see that he calculated the rate at which any group becomes more like they wish to be, by taking great care about whom they marry, and letting those who don’t wish to follow that life to leave the group. The example studied is of a particular religious group in America, the Amish, but selection for desired characteristics applies to all groups.

The next generation of children will have an average Amish Quotient of 0:10 standard deviations greater than their parents did before emigration. The process of selective emigration repeats so that the mean Amish Amish Quotient increases by one tenth of a standard deviation per generation. With 25 years per generation, “Amishness" will increase by a full standard deviation in 10 generations or 250 years. This is substantial social evolution on a time scale of a few centuries.

So, for the English to become one standard deviation more English, only 250 years are required.

In praise of a man bred for civility:


  1. Aye, it's a pity that the good'uns have to die too.

    "for the English to become one standard deviation more English, only 250 years are required": and for them to become one SD less English about 25 years.

  2. I did not know Dr. Harpending, but I was an admirer. What was most influential for me was his 1982 article.


    Patricia Draper
    Henry Harpending

    1. Thanks. A fascinating paper, with a great range of content and the capacity to tie it all together. Talk about individual differences in ability!

  3. What is the year that will arrive in bookstores the book '' the natural history of European intelligence '' ***

    And when it is that scientists will study the brain of Nikola Tesla and show everyone how smart via media was this white serbian ***

    ;) ;) ;)