Achievement beyond IQ: group differences

Last Updated on April 24, 2021

In previous posts, I emphasized the predictive power of cognitive ability on a variety of outcomes such as academic achievement, educational attainment, occupational prestige, income, and crime. I referenced studies showing that adolescent cognitive ability is a better predictor of many of these outcomes than many other metrics traditionally understood to predict success – e.g. parental SES, parental income, and parental education.

But cognitive ability isn’t everything. In another post, I also showed evidence that other indicators – namely, those under the umbrella of “self-regulation” – are also great predictors of success. This post will provide more evidence of the existence of non-IQ factors that have a tremendous impact on success. I will present specific examples of group differences in success that are not the result of group differences in cognitive ability. I begin by citing evidence that Asian American overachievement in a variety of metrics of success – e.g., academic achievement, income, occupational prestige, etc. – are not entirely (or sometimes even primarily) the result of an advantage in cognitive ability. In the future, I plan to add data to this post showing that other groups – including Jews, women, and certain groups of black people – also achieve more than what would be predicted based on their intelligence.

Asian Americans outperform white Americans by a significant margin in a wide variety of metrics, including academic achievement, educational attainment, occupational prestige, income, and avoidance of criminality. While Asian Americans also tend to have slightly higher IQs, I will present evidence from other researchers showing that Asian overachievement cannot be entirely explained by their higher IQs. First, I will describe the many ways in which Asian Americans outperform white Americans.

Recent data [archived] published by the US Census can be used to show Asian Americans overachievement in terms of income, occupational prestige, and marital status as of 2019. Some interesting points include:

  • The median household income for Asian American households ($94k) was much greater than that for white ($72k) and black (44k) households. Also, the median earnings of full-time, year-round, male workers for Asian American individuals (71k) were much greater than that for white (61k) and black (41k) individuals.
  • The percentage of the civilian employed population working in management, business, science, and arts occupations for Asian American workers (55%) was much greater than the same percentage for white (45%) and black (31%) workers.
  • The bachelor degree attainment rate for Asian Americans (31%) was greater than the rate for whites (23%) and blacks (14%). Further, graduate or professional degree attainment rate for Asian Americans (25%) was far greater than the rate for whites (14%) and blacks (9%).

Keep in mind that the majority of Asian Americans were foreign-born, which means that many of them may have acquired these credentials before migrating to the United States. So a more apt comparison may involve comparing Asian Americans and white Americans still attending schools within the United States. Using data from the National Center for Education Statistics (NCES), we can see that Asian American students substantially outperform white students in middle- and high-school.

  • In 2019, Asian Americans outperform other races on the mathematics scale of the National Assessment of Educational Progress (NAEP). The mathematics scale score for Asian Americans (313) was greater than the score for whites (291) and blacks (259). Also, the percentage of 8th graders who demonstrated proficiency in mathematics for Asian Americans (64%) was greater than the percentage for whites (44%) and blacks (14%).
  • In 2019, Asian Americans also outperform other races on the reading scale of the National Assessment of Educational Progress (NAEP). The reading scale score for Asian Americans (284) was greater than the score for whites (271) and blacks (244). Also, the percentage of 8th graders who demonstrated proficiency in reading for Asian Americans (57%) was greater than the percentage for whites (42%) and blacks (15%).
  • Asian Americans also outscore other groups in college entry standardized tests. The average ACT composite score for Asian Americans (24.5) was higher than the average score for whites (22.2) and blacks (16.9). Also, the average total SAT score for Asian Americans (1223) was higher than the average total score for whites (1123) and blacks (946).

Recent data [archived] by the NCES shows NAEP test scores by race among 12th-grade students in 2013. The data indicates that controlling for parental education (one common measure of parental socioeconomic status) mostly eliminates the Asian American advantage over white students in reading scores. However, Asian Americans still outscore all other groups in mathematics at every level of parental education. In fact, Asian American students with parents who did not finish high school outscored black students with parents who graduated from college. Further, the mathematics score for Asian American students with parents who graduated from high school (165) was only slightly lower than the mathematics score for white students with parents who graduated from college (170).

Asian American achievement beyond cognitive ability

The best evidence of Asian American overachievement comes from research by James Flynn, who analyzed the intelligence of young Asian American children as well as their corresponding achievement. Flynn found that the achievements of the Asian Americans in academic achievement, income, and occupation far exceeded what would be expected based on their IQ alone. Much of the data for Flynn’s research is presented in his 1991 book Asian Americans: Achievement beyond IQ, which is not available online. Fortunately, Flynn presented a summary of this research in a chapter of the book Uses and Abuses of Intelligence (2008). In the chapter, Flynn challenges prior studies that allegedly found higher IQs for Asian American children. He criticizes these past findings because they overestimated Asian American IQ due to obsolete norms and sampling deficits. In a reanalysis of studies measuring the IQs of Japanese and Chinese American grade and high school students, Flynn finds that “between 1960 and 1975, these children had a mean IQ slightly below that of their White counterparts” (page 418). Among the studies that measured the IQs of a representative sample of Japanese and Chinese American school children, the average IQ for these children ranged from 95 and 98 (Table 18.1). Flynn focuses on the children born between 1945 and 1949. He finds that, despite having a slightly below average IQ, Chinese and Japanese American school children significantly outperformed white students in terms of scholastic achievement, occupational prestige, and income. Consider the following findings:

  • Compared to whites, Chinese and Japanese Americans were half as likely to lag a grade or more behind their age group (page 418).
  • The high school graduation rate for Chinese/Japanese Americans was 95%, compared to 89% for whites (page 418).
  • Chinese/Japanese American students matched white’s performance on the SAT, despite the fact that more than 50% of Chinese/Japanese students took the test, compared to less than 30% of whites (page 418).
  • By the time the children reached their early 30s, 55% of the Chinese American cohort and 46% of the Japanese American cohort were in high status occupations. By comparison, only 34% of white Americans were in high status cohorts (page 418). “High status” occupations are defined as “managerial, professional, and technical occupations.”
  • The Chinese and Japanese earned annual incomes that were about $2k more than what would be expected based on their IQ alone (page 422). For reference, the average income for whites at this time was about $15,704 (Table 18.4).

So it is clear that Asian Americans far exceeded what would be expected of their IQ. In fact, Table 18.3 shows that, if we were to estimate the IQs of Chinese and Japanese Americans based on their occupational success, we would predict their IQs to be 20 and 10 points, respectively, greater than their actual IQs. In other words, as Neisser et al. (1996) [archived] put it, Flynn found that “that the occupational success of these Chinese Americans–whose mean IQ was in fact slightly below 100–was what would be expected of a White group with an IQ of almost 120! A similar calculation for Japanese Americans shows that their level of achievement matched that of Whites averaging 110” (page 92). Similar patterns were found when predicting Chinese/Japanese American IQs based on income. Flynn reported that Chinese/Japanese Americans accomplished levels of success that would be expected of a white population with IQs that were about 15 points higher (Table 18.4).

Richard Nisbett reported similar findings from Flynn in his 2009 book Intelligence and How to Get It: Why Schools and Cultures Count. Nisbett reported the findings from Flynn specifically for children in the Coleman report, a study published in 1966 that measured the intelligence of a very large random sample of American children. Nisbett reports Flynn’s findings that, again, the Chinese American students outperformed white Americans despite having slightly lower IQ scores (page 156):

Despite their slightly inferior performance on IQ tests, the Chinese Americans of the class of 1966 were about half as likely as other children to have to repeat a grade in K-12 . Foreshadowing things to come, when the Chinese American children were compared with European American children in grade school, they did slightly better on achievement tests. By the time they were in high school, the Chinese Americans were scoring one-third of a standard deviation higher than European Americans on achievement tests. At a given IQ level, the Chinese Americans performed one-half of a standard deviation higher on typical achievement tests, compared with European Americans. The overachievement was particularly great on mathematics tests. In tests of calculus and analytic geometry, the Chinese Americans surpassed European Americans by a full standard deviation. When students were seniors in high school, the Chinese Americans performed about one-third of a standard deviation better on SAT tests than did Americans of the same IQ.

One might try to explain the Asian American overachievement by assuming that the Asian Americans came from households with higher socioeconomic status (SES). Comments by Flynn suggest that this explanation is not likely. Flynn notes that the cohort of Chinese and Japanese Americans that he studied, those born between 1945 and 1949, did not come from households with privileged SES (page 423):

Our best estimate of the size of the IQ/achievement gap is 21 IQ points for Chinese, 10 points for Japanese. I should add a qualification from the perspective of 2006. Recent studies tend to show that today’s Chinese and Japanese Americans have a modest IQ advantage on whites. They, of course, are children and grandchildren of the Chinese and Japanese Americans I have analyzed, namely, those born between 1945 and 1949. The earlier generation came from homes of average socio-economic status and had average IQs or slightly below. Their high incomes and occupational status have given their offspring advantages they did not enjoy, so it is no surprise that the child has surpassed the parent for IQ. That in itself does not mean that the occupation/achievement gap is any less for today’s Chinese and Japanese Americans. I leave that study to a younger scholar.

Other data suggests that Asian American overachievement cannot be entirely explained by the superior SES of their parents. For example, Hsin and Xie (2014) has cited research showing the inadequacy of SES-explanations to account for Asian American overachievement:

The first explanation suggests that Asian-American youth’s academic advantage can be attributed to advantages in socio-demographic factors. Relative to whites, their parents tend to be better educated, and they are more likely to live in stable, two-parent families with higher incomes (5). This explanation, however, is insufficient because advantages in socio-demographic factors only partially explain the achievement gap (2, 3, 5). Moreover, Asian Americans are not uniformly advantaged in terms of family socioeconomic background. For example, the poverty rates of Chinese and Vietnamese are higher than they are for whites (5). However, the disadvantaged children of Chinese and Vietnamese immigrant families routinely surpass the educational attainment of their native-born, middle-class white peers (6, 7).

Non-cognitive skills

So clearly neither intelligence (as measured by IQ scores) nor SES can fully explain Asian American overachievement. So what explains why Asian Americans tend to outperform equally intelligent whites from households with similar SES? Before answering this question, I should note that there are plenty of predictors of success other than intelligence and parental SES, some which even have greater predictive power than intelligence. Consider the following predictors of success:

  • I have written elsewhere on the importance of self-regulation for success. There have been plenty of studies showing that childhood self-regulation predicts adulthood success even after controlling for IQ and parental SES (Moffitt et al. 2011, pages 2694-2695; Fergusson et al. 2013, Table 3). Some studies have even shown that self-control may be more important than intelligence for certain measures of academic achievement. For example, Duckworth et al. (2012) [archived] conducted two longitudinal studies of middle school students and found that self-control had a larger impact on report card grades than intelligence (although intelligence had a larger impact on standardized achievement test scores).
  • Contentiousness has also been shown to predict success independently of intelligence. For example, contentiousness has been shown to predict occupational performance (Hurtz and Donovan 2000, table 2; Dudley et al. 2006, Table 4). Impressively, contentiousness has sometimes been shown to predict academic achievement almost as well as intelligence (Poropat 2008, Table 2; Abraham et al. 2012, Table 4).

Traits such as these have been called “non-cognitive” skills because they are psychological/behavioral traits related to success which can be disassociated from cognitive ability (i.e., intelligence). There is some evidence that Asian Americans outperform other groups in many non-cognitive skills:

  • Goldammer (2012) analyzed racial differences in non-cognitive skills using data from the ECLS-K, which involved over 21,260 children between kindergarten and 8th grade. He found that Asian students had a 0.5 standard deviation “advantage over Whites in teacher-rated noncognitive skills” (page 22). The non-cognitive skills was measured as a composite of self-control, interpersonal, externalizing, and internalizing skills (page 20).
  • Nguyen et al. (2019) compared the non-cognitive skills of children of Asian immigrants with children of other immigrant parents in Australia. Researchers found that “from teachers’ ratings, children of Asian immigrants achieve higher scores than children of other parents in almost all non-cognitive attributes across the school years” (Figure 1, page 14). They also found no ethnic differences in non-cognitive skills among third-generation children, suggesting that the initial differences may be the result of cultural rather the biological causes (page 14). Non-cognitive skills were measured based on a composite that consists of a pro-sociality, hyperactivity, emotional, conduct, and peer scale (Appendix Table A1).

Other studies have shown that Asian American students outperform white students after controlling for parental socioeconomic status and cognitive ability. For example, Hsin and Xie (2014) used data from the ECLS-K to compare the academic achievement of white students and certain Asian American groups (East Asians, Filipinos, Southeast Asians, and South Asians). They found that each of these “Asian ethnic groups outperform whites in academic achievement, including Southeast Asians, who came from poorer and less educated families relative to whites” (page 8418). Differences in SES are poor explanations of the Asian American advantage because they note that “Controlling for sociodemographic factors explains at most about 30% of the achievement gap in 9th grade; in 11th and 12th grades, the gap actually increases with the inclusion of socio-demographic controls” (page 8418). Differences in cognitive ability are also poor explanation of the Asian American advantage because “only East Asians have a sizable advantage in cognitive ability”. Instead, researchers conclude that the Asian American advantage is primarily the result of greater academic effort (page 8418):

In eighth grade, between 9% and 58% of this gap is attributed to cognitive ability but between 42% and 91% is attributed to academic effort. In 12th grade, between 1% and 25% is attributed to cognitive ability, but between 75% and 101% is attributed to academic effort. In sum, the results suggest that Asian Americans’ greater academic effort primarily explains their achievement advantage; the explanatory power of socio-demographics and cognitive ability are both limited.

The authors consider two possible explanations for Asian American overachievement: immigration status and a culture that emphasizes “the strong connection between effort and achievement” (page 8419). The effects of this culture appears to wane over time because third-generation Asian Americans “no longer differ from whites in terms of their educational profiles” (page 8419), suggesting that these non-cognitive skills may not be the result of a biological predisposition of students with higher levels of Asian ancestry. Other studies have also considered the possibility that culture may explain Asian American overachievement (Liu and Xie 2014).  Flynn (2008) considered the possibility that the special history of Chinese Americans which may have fostered cultural norms that place a relatively strong importance on education (pages 425-429). Whatever the true cause of Asian American overachievement, it is clear that Asian Americans far exceed what would be expected given their cognitive ability and parental SES.