1500 words

Jewish IQ is one of the most-talked-about things in the hereditarian sphere. Jews have higher IQs, Cochran, Hardy, and Harpending (2006: 2) argue due to “the unique demography and sociology of Ashkenazim in medieval Europe selected for intelligence.” To IQ-ists, IQ is influenced/caused by genetic factors—while environment accounts for only a small portion.

In The Chosen People: A Study of Jewish Intelligence, Lynn (2011) discusses one explanation for higher Jewish IQ—that of “pushy Jewish mothers” (Marjoribanks, 1972).

“Fourth, other environmentalists such as Majoribanks (1972) have argued that the high intelligence of the Ashkenazi Jews is attributable to the typical “pushy Jewish mother”. In a study carried out in Canada he compared 100 Jewish boys aged 11 years with 100 Protestant white gentile boys and 100 white French Canadians and assessed their mothers for “Press for Achievement”, i.e. the extent to which mothers put pressure on their sons to achieve. He found that the Jewish mothers scored higher on “Press for Achievement” than Protestant mothers by 5 SD units and higher than French Canadian mothers by 8 SD units and argued that this explains the high IQ of the children. But this inference does not follow. There is no general acceptance of the thesis that pushy mothers can raise the IQs of their children. Indeed, the contemporary consensus is that family environmental factors have no long term effect on the intelligence of children (Rowe, 1994).

The inference is a modus ponens:

P1 If p, then q.

P2 p.

C Therefore q.

Let p be “Jewish mothers scored higher on “Press for Achievement” by X SDs” and let q be “then this explains the high IQ of the children.”

So now we have:

Premise 1: If “Jewish mothers scored higher on “Press for Achievement” by X SDs”, then “this explains the high IQ of the children.”
Premise 2: “Jewish mothers scores higher on “Press for Achievement” by X SDs.”
Conclusion: Therefore, “Jewish mothers scoring higher on “Press for Achievement” by X SDs”  so “this explains the high IQ of the children.”

Vaughn (2008: 12) notes that an inference is “reasoning from a premise or premises to … conclusions based on those premises.” The conclusion follows from the two premises, so how does the inference not follow?

IQ tests are tests of specific knowledge and skills. It, therefore, follows that, for example, if a “mother is pushy” and being pushy leads to studying more then the IQ of the child can be raised.

Looking at Lynn’s claim that “family environmental factors have no long term effect on the intelligence of children” is puzzling. Rowe relies heavily on twin and adoption studies which have false assumptions underlying them, as noted by Richardson and Norgate (2005), Moore (2006), Joseph (2014), Fosse, Joseph, and Richardson (2015), Joseph et al (2015). The EEA is false so we, therefore, cannot accept the genetic conclusions from twin studies.

Lynn and Kanazawa (2008: 807) argue that their “results clearly support the high intelligence theory of Jewish achievement while at the same time provide no support for the cultural values theory as an explanation for Jewish success.” They are positing “intelligence” as an explanatory concept, though Howe (1988) notes that “intelligence” is “a descriptive measure, not an explanatory concept.” “Intelligence, says Howe (1997: ix) “is … an outcome … not a cause.” More specifically, it is an outcome of development from infancy all the way up to adulthood and being exposed to the items on the test. Lynn has claimed for decades that high intelligence explains Jewish achievement. But whence came intelligence? Intelligence develops throughout the life cycle—from infancy to adolescence to adulthood (Moore, 2014).

Ogbu and Simon (1998: 164) notes that Jews are “autonomous minorities”—groups with a small number. They note that “Although [Jews, the Amish, and Mormons] may suffer discrimination, they are not totally dominated and oppressed, and their school achievement is no different from the dominant group (Ogbu 1978)” (Ogbu and Simon, 1998: 164). Jews are voluntary minorities, and voluntary minorities, according to Ogbu (2002: 250-251; in Race and Intelligence: Separating Science from Myth) suggests five reasons for good test performance from these types of minorities:

1. Their preimmigration experience: Some do well since they were exposed to the items and structure of the tests in their native countries.
2. They are cognitively acculturated: They acquired the cognitive skills of the white middle-class when they began to participate in their culture, schools, and economy.
3. The history and incentive of motivation: They are motivated to score well on the tests as they have this “preimmigration expectation” in which high test scores are necessary to achieve their goals for why they emigrated along with a “positive frame of reference” in which becoming successful in America is better than becoming successful at home, and the “folk theory of getting ahead in the United States”, that their chance of success is better in the US and the key to success is a good education—which they then equate with high test scores.

So if ‘intelligence’ is a test of specific culturally-specific knowledge and skills, and if certain groups are exposed more to this knowledge, it then follows that certain groups of people are better-prepared for test-taking—specifically IQ tests.

The IQ-ists attempt to argue that differences in IQ are due, largely, to differences in ‘genes for’ IQ, and this explanation is supposed to explain Jewish IQ, and, along with it, Jewish achievement. (See also Gilman, 2008 and Ferguson, 2008 for responses to the just-so storytelling from Cochran, Hardy, and Harpending, 2006.) Lynn, purportedly, is invoking ‘genetic confounding’—he is presupposing that Jews have ‘high IQ genes’ and this is what explains the “pushiness” of Jewish mothers. The Jewish mothers then pass on their “genes for” high IQ—according to Lynn. But the evolutionary accounts (just-so stories) explaining Jewish IQ fail. Ferguson (2008) shows how “there is no good reason to believe that the argument of [Cochran, Hardy, and Harpending, 2006] is likely, or even reasonably possible.” The tall-tale explanations for Jewish IQ, too, fail.

Prinz (2014: 68) notes that Cochran et al have “a seductive story” (aren’t all just-so stories seductive since they are selected to comport with the observation? Smith, 2016), while continuing (pg 71):

The very fact that the Utah researchers use to argue for a genetic difference actually points to a cultural difference between Ashkenazim and other groups. Ashkenazi Jews may have encouraged their children to study maths because it was the only way to get ahead. The emphasis remains widespread today, and it may be the major source of performance on IQ tests. In arguing that Ashkenazim are genetically different, the Utah researchers identify a major cultural difference, and that cultural difference is sufficient to explain the pattern of academic achievement. There is no solid evidence for thinking that the Ashkenazim advantage in IQ tests is genetically, as opposed to culturally, caused.

Nisbett (2008: 146) notes other problems with the theory—most notably Sephardic over-achievement under Islam:

It is also important to the Cochran theory that Sephardic Jews not be terribly accomplished, since they did not pass through the genetic filter of occupations that demanded high intelligence. Contemporary Sephardic Jews in fact do not seem to haave unusally high IQs. But Sephardic Jews under Islam achieved at very high levels. Fifteen percent of all scientists in the period AD 1150-1300 were Jewish—far out of proportion to their presence in the world population, or even the population of the Islamic world—and these scientists were overwhelmingly Sephardic. Cochran and company are left with only a cultural explanation of this Sephardic efflorescence, and it is not congenial to their genetic theory of Jewish intelligence.

Finally, Berg and Belmont (1990: 106) note that “The purpose of the present study was to clarify a possible misinterpretation of the results of Lesser et al’s (1965) influential study that suggested that existence of a “Jewish” pattern of mental abilities. In establishing that Jewish children of different socio-cultural backgrounds display different patterns of mental abilities, which tend to cluster by socio-cultural group, this study confirms Lesser et al’s position that intellectual patterns are, in large part, culturally derived.” Cultural differences exist; cultural differences have an effect on psychological traits; if cultural differences exist and cultural differences have an effect on psychological traits (with culture influencing a population’s beliefs and values) and IQ tests are culturally-/class-specific knowledge tests, then it necessarily follows that IQ differences are cultural/social in nature, not ‘genetic.’

In sum, Lynn’s claim that the inference does not follow is ridiculous. The argument provided is a modus ponens, so the inference does follow. Similarly, Lynn’s claim that “pushy Jewish mothers” don’t explain the high IQs of Jews doesn’t follow. If IQ tests are tests of middle-class knowledge and skills and they are exposed to the structure and items on them, then it follows that being “pushy” with children—that is, getting them to study and whatnot—would explain higher IQs. Lynn’s and Kanazawa’s assertion that “high intelligence is the most promising explanation of Jewish achievement” also fails since intelligence is not an explanatory concept—a cause—it is a descriptive measure that develops across the lifespan.