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For those trying to justify Watson's speculation that the average racial gap in IQ scores "is genetic” since 1) IQ is partially inherited from parents 2) we know a gap exists: please see quote from prominent IQ researcher @RobertPlomin in my article. nytimes.com/2019/01/01/sci… MORE
I sought out @RobertPlomin’s comments precisely because he has staked out the extreme end of the nature-and-nurture continuum. His book is “Blueprint: How DNA Makes Us Who We Are.” His recent piece for @sciam is “In the Nature-Nurture War, Nature Wins.’’ blogs.scientificamerican.com/observations/i…
Plomin chose not to comment on Watson. But he very kindly sent me the unedited draft of the Afterward for the paperback edition of his book, to be published this spring. In it, he replies to some of the criticisms it received.
“One of these criticisms is that Blueprint does not discuss group differences,’’ Plomin wrote in his email to me, “including ethnic group differences.’’
Here is the quote that I used in the story: “There are powerful methods for studying the genetic and environmental origins of individual differences, but not for studying the causes of average differences between groups.” It's right in here, see:: nytimes.com/2019/01/01/sci…
I will now paste in a longer excerpt from the Afterword-draft that Plomin sent me: "Blueprint explains why it is crucial to distinguish between individual differences and group differences: ‘It is an important principle that the causes of average differences between groups..."
...are not necessarily related to the causes of individual differences within groups. … This principle also applies to more politically sensitive differences between groups such as average differences between males and females, social classes, or between ethnic groups.’ (p. 194)
"In other words, individual differences can be highly heritable for a trait but that does mean that average differences between groups for that trait are also caused genetically."
"There are two main reasons why I have steered away from group differences. The first is that most differences are within groups rather than between groups. That is, if all you know about a person is a group to which they belong, you know very little about who they are... "
...as an individual. The second reason is that there are powerful methods for studying the genetic and environmental origins of individual differences but not for studying the causes of average differences between groups...."
"I think this is why there is so much heat and so little light in understanding the origins of group differences." [END OF EXCERPT]
Yikes important typo in this one! Should read: "In other words, individual differences can be highly heritable for a trait but that doesn't mean that average differences between groups for that trait are also caused genetically.” cc @RobertPlomin
