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Jul 12, 2022, 19 tweets

[THREAD]

A VERY BASIC INTRODUCTION TO THE HEREDITARIAN POSITION ON RACE AND IQ.

PART 1: Introduction.

1/ Persistent differences in the average IQ of different groups (including races) have been the subject of study by scientists for decades, although most of this research has been conducted quietly and out of the view of the public due to its sensitive nature.

2/ The existence of gaps in average IQ between the races is now firmly established, and is no longer controversial among scientists who study human intelligence.

3/ The biggest remaining controversy is over the reason for the gaps: Are they due to genetic differences between groups or to differences in the environments to which each is exposed?

4/ But even this central controversy can be more narrowly expressed now that the majority of scientists have come to believe that both genes and environment play at least *some* role in group IQ differences, and the question has therefore become:

5/ How *much* of a particular gap — for example, that between Americans of African ancestry and Americans of European ancestry — is due to the influences of the environment (“nurture”), and how *much* to differences in genetic make-up (“nature”)?

6/ Stated differently: Most scientists studying human intelligence believe race IQ gaps are due to a combination of *both* genetic and environmental factors.

The only real controversy is over the share of each.

The share of each may be anywhere from near-total to negligible.

7/ Before going any further, I should state that these threads will be of more interest to intelligent laymen who have had limited exposure to the subject, and will be of less interest to those already possessing a strong familiarity or expertise.

8/ Please note that because of its small population size, I'm probably going to be leaving out of my discussion Ashkenazi Jewish IQ, believed by intelligence researchers to be higher than the average of any other group, with estimates ranging from 108 to 118.

9/ This extraordinary Ashkenazi cognitive advantage no doubt explains why a group that comprises well under 1% of the world's population has received about a quarter of all science Nobel Prizes, an astonishing accomplishment.

10/ Also, a word about “Asians”. This obviously includes many different groups, with widely-varying average IQs (from 80 to 108), but in the US includes mostly northeast Asians (i.e., Chinese, Japanese, and Koreans) and south Asians (i.e., from the Indian subcontinent).

11/ Apart from Ashkenazi Jews, northeast Asians have the highest average IQ in the world (around 105). South Asians, on average, fare more poorly, but those who emigrate to the US (especially from India) tend to have IQs well above the south Asian average.

12/ Most of the discussion will relate to the IQ gap between Americans of European ancestry and Sub-Saharan African ancestry because that's where most the data are and, as an American, this gap has greater social, cultural, political, and economic implications than any other.

13/ I probably won't be discussing Hispanics — it's a US Census category and not really a useful one for genetic ancestry, as it may include, for example, a Colombian-American with 90% European ancestry and a Dominican-American with 90% African ancestry.

14/ Also discussed only very briefly will be world IQ scores, including Sub-Saharan African scores, which are the lowest in the world, lower than African-American scores.

15/ When the term “environment” is used in these threads I mean everything other than genetic influences — things like education, socioeconomic status, parental influence, life events, prenatal factors, dietary deficiencies, illnesses, random events, etc.

16/ Note that I'm going to be using the terms “IQ” and “intelligence” interchangeably in these threads because the great majority of researchers believe that IQ tests measure intelligence accurately and also because using “IQ” uses fewer Twitter characters (no small thing).

17/ Finally, I'll state that although I retain an open mind, I believe that the arguments for genetic factors in the race IQ gaps are generally more convincing than those for environmental ones; therefore I believe genetics play a not-insignificant role in these differences.

18/ As a result, the threads will usually be framed from a hereditarian-leaning perspective. At the same time, however, I'm not uncritical of occasional shortcomings in the hereditarian explanation, and will be pointing these out.

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