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The Fallacy of the Genetic Determination of Inherent Cognitive Abilities

A new Education Research Brief from Save Our Schools. It demonstrates the fallacy of the genetic determination of inherent cognitive abilities. This is an important issue relevant to the next National Schools Reform Agreement because genetic determinists have long dismissed the Gonski funding loadings for disadvantaged students as a waste of taxpayer funding.

Inequity in education is the key challenge facing Australian education policy. One of the fundamental premises of the approach by Save Our Schools is that the mean and range of intrinsic abilities, however they are defined and measured, should be the same across different social groups, whether defined in terms of social class, ethnicity, or any other broad characteristic. As the Gonski Report stated as justification for its definition of social equity in education:

Central to the panel’s definition of equity is the belief that the underlying talents and abilities of students that enable them to succeed in schooling are not distributed differently among children from different socioeconomic status, ethnic or language backgrounds, or according to where they live or go to school. (1)

This has been a controversial area over many years, with a consistent pattern of assertions that genetics determines class and ethnic/racial differences, through differences in intrinsic cognitive ability, and that, as a result, interventions cannot change differences in educational outcomes by social group. (2) These claims have consistently been contested, often hotly given their social importance, on both direct scientific and practical grounds (3-5). In addition, there has always been evidence that there are major environmental impacts on IQ (6) and that social change and intervention programs can change outcomes, (7) particularly for equity target groups.

A key part of the case for genetic determination was the claims that IQ or intelligence were predominantly inherited, and thus educational outcomes could not be improved. It is important to stress at this stage, that this argument never had any validity, because as pointed out by Visscher et al (8) in their review of heritability in the genomic era, high heritability does not imply genetic determination, precisely because the environment can be changed or manipulated to change phenotype. Our experience over the years is that in the minds of many people there are often vague memories that this issue may has been resolved by the review carried out by the American Psychological Association (APA), which concluded, based on twin studies, that IQ, or cognitive ability, had a significant heritability (50 to 80%), (9) with the implication that there was, at least potentially, a significant genetic basis to social differences. Most of the evidence was obtained with ancestry/ethnic groups predominantly of European or white ancestry and were thus most relevant to class differences. It was generally accepted, albeit not universally, that these conclusions could not be generalised to differences between racial/ethnic groups, (1,8) though this did not prevent some arguing that there was a genetic deterministic difference between racial groups.

In the Australian context, the position based on heritability has been argued by Gary Marks, one of the most trenchant critics of the Gonski approach. Marks argues that the Gonski funding formula cannot succeed because the primary determinant of student achievement is parental abilities that are genetically transmitted to their children. (10) Putting it bluntly, he claims that people from “lower classes” have lower intelligence.(11) While his general argument is that disadvantaged groups are disadvantaged due to their genetic inheritance, he has admitted that this argument specifically applies to socio-economic disadvantage. He has not been so forth-coming about other defined equity groups. It is up to him to explain whether he thinks his arguments apply to other social groups and specifically whether they apply to the low outcomes achieved by Indigenous students.

Over the years, Marks has produced many variations on this theme, using the argument that when “prior student achievement” is included in the analysis of educational outcomes, the contribution from socioeconomic status declines, and often becomes negligible. (12,13) The problem is that if socioeconomic status significantly determines prior student achievement, then the challenge becomes to determine which of the two variables is in fact causally involved. But for Marks, the answer is clear, because his view is that prior student achievement is genetically determined.

Recent progress in research on this topic has further undermined the relevance of heritability as defined by twin studies and has reached the point that estimates of heritability based on more powerful and direct molecular genetic analysis show that the genetic contribution to prior performance or cognitive ability (or IQ) is quite small, with abundant room for environmental factors to play a major role.

Download new Education Research Brief from Save Our Schools.

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