Written by Gary Marks

Socioeconomic status (SES) dominates research, public debate, policy, and politics on social inequality. From early childhood to graduate school, inequalities between children and students are largely attributed to parents’ education, occupational class, income, and/or wealth. Since education is important for subsequent social and economic outcomes, SES is understood as the ultimate source of educational and labor market inequalities in society and for their reproduction across generations. These inequalities are falsely assumed to be profound, pervasive, and persistent.

This is the essence of the SES paradigm. Namely, SES is the key influence for almost every conceivable educational outcome: test scores, grades, examination results, school differences, school and classroom climate, truancy, student misbehavior, and highest educational qualification. Of course, SES adherents also believe that other factors influence student outcomes, such as schools, teachers, parents, and peers. However, according to the SES paradigm, SES is the dominant influence, and these factors mainly mediate SES effects.

What’s more, the differences in student outcomes by race, ethnicity, family size and family structure are assumed to be, at least partly, attributable to SES. SES is believed to be the primary influence on cognitive development among very young and preschool children exerting its influence through material resources (especially income), parental stress, and parenting behavior. Furthermore, it is frequently asserted that SES impacts, either directly or through education, the entire range of labor market outcomes: participation in the labor force, unemployment, occupation, earnings, and career trajectories.

The SES paradigm extends further into health, crime, socio-emotional development, well-being, mental disorders, and delinquency. Occupational class and SES remain part of the rhetoric of political parties and political activists of the left — although the relationship between them and political preference has reversed in many Western countries (Kitschelt & Rehm, 2022).

An alternative to the SES paradigm is the cognitive ability/genetic transmission paradigm. This paradigm contends that the relationships of SES with educational and labor market outcomes are largely spurious. The relationships are due to the associations of parents’ cognitive abilities with their education, occupation, and income; genetic transmission from parents to their biological children; and, within the offspring generation, similar associations of cognitive ability with their educational and occupational attainments. There is considerable evidence for these contentions (Marks & O’Connell, 2023). Thus, the intergeneration correlations of education, occupation, and income are primarily epiphenomena and, therefore, cannot be substantially reduced by policy.

Paradigms

Most readers will be familiar with Kuhn's (1962/1996) The Structure of Scientific Revolutions on scientific paradigms. Normal science is based on a paradigm, a set of practices, beliefs, and a body of knowledge shared by its practitioners and adherents. Scientific paradigms define the legitimate problems and methods of a research field. Its accomplishments attract an enduring group of adherents, but unlike religion or ideology, allow unresolved issues to be investigated scientifically by further research. The paradigm provides an overarching framework encompassing the skills and knowledge required for formulating research questions, their investigation, and the interpretation of findings. A paradigm includes satisfactory theoretical explanations for relevant empirical observations. Within a paradigm, knowledge slowly accumulates through revision, refinement, and the resolution of alternative theories and hypotheses.

Scientific paradigms work well until empirical observations do not conform with the paradigm. Anomalies are first accommodated within the paradigm by minor modifications to the relevant theories. For a while, more serious anomalies can be ignored or dismissed because of uncertainties about data, measures, or methods. A crisis occurs when inconsistencies between theory and empirical observations accumulate so that it is no longer possible to explain or dismiss incongruent findings within the paradigm. A paradigm shift occurs when an alternative paradigm provides far more compelling explanations for relevant empirical observations. The original paradigm remains consistent with many empirical observations, but the original paradigm is further eroded with each new set of findings that cannot be accommodated. Eventually, the original paradigm collapses, although the timing is influenced by the political context (Kuhn, 1962/1996, pp. 66-76). Ritzer (1975) points out that a more meritorious paradigm cannot gain ascendency without winning the political battle. Less worthy paradigms can maintain hegemony through political means despite their inadequacies. This is the case for SES and cognitive ability/genetic transmission paradigms.

Paradigm shifts have occurred despite strong political opposition: for example, the heliocentric solar system (the preeminent exemplar of a paradigm shift); Darwin’s theory of evolution; and in the USSR, Mendelian inheritance. Kuhn discusses paradigm shifts—Maxwell’s equations, relativity theories, and continental drift—that were largely unnoticed because they posed no threat politically to anyone outside the small group of scientists wedded to the original paradigm. Today’s SES paradigm is unique in the depth and breadth of its political support. In contrast, the alternative cognitive ability/genetic transmission paradigm is unpopular since it contradicts cherished political beliefs and ideologies.

Ioannidis (2005) concluded that most research findings in medical science fields are false. The social sciences are likely to fare much worse. Ioannidis (2005) proposed several corollaries that reduce the probability that research findings are true: small effect sizes, lack of replicability; many variations in definitions, analytical designs and findings; and a high degree of prejudice (read political ideology).

The SES paradigm has these characteristics. SES effect sizes are only moderate and are much smaller when considering stronger predictors, for example, cognitive ability. There is very little replicability, but an overabundance of similar analyses purporting to be novel. There is a great variety of theoretical explanations, operational definitions of SES, and statistical approaches. However, there are very few generally agreed-upon conclusions. Almost every point is contested with little or no resolution. Many research fields relating to social inequality in education, sociology, psychology, and economics are highly politicized.

It could be argued the SES and cognitive ability/genetic transmission paradigms do not constitute distinct paradigms at all. Cognitive ability can be simply accommodated within the SES paradigm. Many studies include measures of SES and cognitive ability in the same analysis. However, the two approaches are fundamentally different. The SES paradigm assumes that the effects of SES represent purely sociological processes, for example, home, school, economic, and cultural resources. In contrast, the cognitive ability/genetic transmission paradigm assumes that SES effects include non-sociological processes involving genetic transmission. Furthermore, the SES paradigm assumes that cognitive ability is a product of class background and other factors, with genetics playing no, or a minimal, role (Fischer et al., 1996; Richardson, 2002).

A Collapsing Paradigm

The SES paradigm is collapsing because the very concept of SES is nebulous. Prominent theoretical concepts, such as economic and human capital, are construed to provide post-hoc justifications. There is no consensus on what SES is, and how to measure it. The variables that measure SES are often unreliable and are too weakly intercorrelated to support the contention that SES is a meaningful concept (Marks & O'Connell, 2021).

The collapsing SES paradigm is very evident in theories and explanations for the effects of SES on educational and subsequent socioeconomic outcomes. There is a plethora of theoretical explanations which attempt to explain the relationships emphasizing a limited number of concepts. There is no consensus on why SES matters, just innumerable overlapping theories. The sheer number and variety of theoretical explanations are a testament to their inadequacy.

SES-focused theories become prominent, not because they provide satisfactory explanations for a range of empirical phenomena, which explanatory theories should do, but because they become fashionable for a while and then fade away. Some have greater longevity than others. For a short time, prominent theorists strut the academic stage as if they have discovered something important, like a latter-day Newton or Darwin.

The ultimate reason that most theories of SES inequalities go in and out of fashion is that they cannot account for the empirical phenomena they purport to explain. Furthermore, they ignore the fundamental empirical realities that SES effects are, at best, only moderate. The strong possibility that these effects substantially reflect parental abilities and their genetic transmission is almost universally ignored. Theories that are only weakly supported empirically and ignore inconvenient but highly relevant findings should not and cannot survive as scientific theories.

The cognitive ability/genetic transmission paradigm is superior. It has much greater explanatory power and explains the observed relationships involving SES. It can account for empirical phenomena that the SES paradigm cannot.

It is well-established that intelligence (cognitive ability) is a valid and measurable concept. The numerous myths surrounding the concept, its measurement, and its importance have been debunked by extensive literature that has accumulated over the last century (Warne, 2020). For student achievement, educational and occupational attainment, and income and wealth, cognitive ability has greater explanatory power than comprehensive measures of SES. It accounts for a large proportion of the effects of SES, whereas SES only minimally accounts for the effects of cognitive ability (Marks, 2022). The effects of SES on cognitive ability and student achievement are primarily accounted for by the mother’s cognitive ability (Marks & O’Connell, 2023).

Furthermore, the most important variables involved in social stratification—cognitive ability, student achievement, educational and occupational attainment and income—all have sizeable heritabilities, that is the proportion of the variation in a trait attributable to genetic differences (de Zeeuw, de Geus, & Boomsma, 2015; Plomin & Deary, 2015; Pokropek & Sikora, 2015; Hyytinen, Ilmakunnas, Johansson, & Toivanen, 2019; Silventoinen et al., 2020). The causal implications of high heritabilities cannot be dismissed (Egeland, 2023).

The much stronger explanatory power of cognitive ability and the sizable genetic components to social stratification outcomes are incompatible with the SES paradigm. The paradigm collapses because it is unable to account for these findings. Therefore, the vast SES-centred theoretical and empirical literature is rendered highly questionable, if not irrelevant. In addition, cognitive ability and genetics account for the lack of success for policies emanating from the SES paradigm aiming to eliminate, or at least substantially reduce, socioeconomic inequalities. It also explains why parents’ socioeconomic characteristics still matter under socialism and in the Kibbutz (Firkowska et al., 1978; Justman & Gilboa, 2012).

Sources of Support

Given that the vast majority of SES-centered theories have poor explanatory power and are misleading because they ignore cognitive ability and genetics, why does the SES paradigm remain dominant? It survives because it is central to so much academic research, policy formulation, and political discourse. Its fundamental contention that educational inequality, and societal inequalities more generally, can be attributed to socioeconomic origins is largely unquestioned across academia, research institutes, government bureaucracies, international agencies (e.g. the OECD), the commentariat, social media, teacher unions, the political left and even the political right. The adage that paradigms change ‘funeral-by-funeral’ does not apply to the SES paradigm given its high level of political support. For more, see Peter Saunders’ excellent article in this publication:

Ideas Sleep Furiously

Why does everybody lie about social mobility?

Written by Peter Saunders. Before the Second World War, a child’s chance of succeeding in Britain’s educational system depended to a large extent on the size of their parents’ wallet. In those days, half of the places in state-aided grammar schools went to fee-paying students. Many bright children from poorer backgrounds got excluded because parents of…

8 months ago · 24 likes · 8 comments

Academia

In the social sciences, each new cohort of students is exposed to the SES paradigm. Many academics have built successful careers around some aspect of SES; perhaps by becoming an expert in a particular theory or theorist; proposing a slightly different theoretical explanation; resurrecting an old one; or by publications highlighting SES or occupational class. They work within the SES paradigm. Most academic journal editors and referees accept the major tenets of the SES paradigm. It provides fertile, although very much over-tilled, ground for journal articles, books and book chapters, research grants, and PhD theses. This has been happening with little progress for over 50 years and is unlikely to change anytime soon. The lack of an accumulating largely consensual body of knowledge about educational and other societal inequalities is because of the hegemony of the SES paradigm.

Critical theory and post-modernism are also concerned with social inequality. However, they are not scientific, often explicitly rejecting scientific assumptions, methods, and practices. Importantly, they deny the possibility of objective knowledge. However, they are accepted as academic disciplines with all their paraphernalia of conferences, journals, and research grants. They are not rejected from academia for being unscientific and highly politicized because their general political orientation is consistent with that of the SES paradigm. So highly tendentious ‘research’ that does not adhere to the evidentiary rules of normal science has become quite acceptable. This is disastrous for the accumulation of scientific knowledge and effective policies.

Academic research into social inequality has been strongly influenced by Marxism. Much of the inspiration for stratification research comes from the belief that socioeconomic inequality is morally repugnant and the need to understand the (capitalist) system to change it. The focus on occupational class stems directly from Marxism and its critics, most prominently Max Weber. Many of the theoretical accounts for socioeconomic inequalities have Marxist legacies. For example, cultural capital theory purports to explain class inequalities with an emphasis on social exclusion and cultural hegemony. During the 1970s and 1980s, there was an enduring, and ultimately fruitless debate on Marxist and Weberian approaches to class. Many of the most strident critics of cognitive ability and behavioral genetics were self-identified Marxists (e.g., Gould, Lewontin, & Kamin).

Politics

The SES paradigm is central to the political agenda of left-wing political parties and activists.

For the moderate left, socioeconomic inequality is a problem that can be alleviated by policies. Once in power, left-wing political parties, which invariably adhere to the SES paradigm, promote, debate, implement policies, and fund research consistent with the SES paradigm. Notably, they ignore similar policies that have failed in the past. Academic research is cherry-picked to support the party’s political position and proposed policies. Opposition is depicted as insensitive, ignoring, if not supporting, socioeconomic inequality. Since research communities and education bureaucracies generally accept the SES paradigm holus-bolus, center-right governments tend to do the same.

The SES paradigm is a major plank of far-left politics. The supposedly strong and enduring SES inequalities is further evidence of the iniquity of Western capitalist societies. No amount of contrary empirical evidence will change this belief, despite enormous improvements in wealth, health, and living standards, substantial reductions in real poverty, the expansion of social welfare and other government services, and the implementation of policies specifically designed to reduce socioeconomic and other inequalities.

What are the far-left policy prescriptions to combat the reproduction of socioeconomic inequalities which they incorrectly understand as profound, pervasive, and persistent? Generally, it is state control of all the major societal institutions. Entry to elite educational institutions would not be based on academic performance but by bureaucrats using political criteria. Similarly, the state would be involved in hiring, promotion, and dismissal in workplaces. They advocate intellectuals (like themselves) leading an agenda of radical social reform to obliterate disparities — a model that has historically proved disastrous wherever implemented.

A larger political agenda

No research in cognitive psychology or behavioral genetics argues that social outcomes are biologically determined. No one identifies as a ‘genetic determinist’ or makes that argument. Behavioral genetics does not dismiss the role of the environment; the shared and unshared environment are fundamental concepts. Likewise, no one argues that heritability applies to individuals and is immutable across time and societies (see Sesardić, 2005).

There is no logical connection between cognitive IQ research and apartheid, Jim Crowe laws, or sanctioned racism, which still exists in many countries. Much of the support for eugenics in the late 19th and early 20th centuries was from progressives and socialists (Freeden, 1979; Paul, 1984).

Yet, the cognitive ability/genetic transmission paradigm has been attacked as being offensive to low SES families and social minorities. This critique is not about sensibilities but, again, a political ploy to silence criticism of the SES paradigm. There is a vast industry and prominent political ideologies to protect.

Although the language surrounding explanations for SES inequalities in education is usually couched in a sympathetic tone, explanations within the SES paradigm could also be considered offensive. For example, less educated parents are uninterested in their children’s education; do not value education; have negative attitudes towards academic pursuits; use fewer words and less complex language; do not read enough to their children; have poor parenting practices; their communities’ norms and values are antithetical to educational success; and they lack the cultural knowledge, (whatever that is) necessary for success in modern education systems.

So why are the attacks on cognitive psychology and behavioral genetics so vehement? It is because the cognitive ability/genetic transmission paradigm poses a serious, scientifically rigorous challenge to left-wing sensibilities. The SES paradigm, although failing as an explanatory model, survives not because of science, but because of ideology.

Gary N. Marks is an honorary principal fellow in the Department of Sociology, Social and Political Sciences at the University of Melbourne. He has publications in four main areas: educational outcomes, labor market outcomes and social outcomes. His work has a particular emphasis on changes over time and cross-national differences in social stratification, social inequality and the contribution of cognitive ability and genetics to educational and socioeconomic outcomes.

Bibliography

de Zeeuw, E. L., de Geus, E. J. C., & Boomsma, D. I. (2015). Meta-analysis of twin studies highlights the importance of genetic variation in primary school educational achievement. Trends in Neuroscience and Education, 4(2015), 69–76. doi:https://doi.org/10.1016/j.tine.2015.06.001.

Egeland, J. (2023). Heritability and etiology: Heritability estimates can provide causally relevant information. Personality and Individual Differences, 200, 111896. doi:https://doi.org/10.1016/j.paid.2022.111896.

Firkowska, A., Ostrowska, A., Sokolowska, M., Stein, Z., Susser, M., & Wald, I. (1978). Cognitive development and social policy. Science, 200(4348), 1357-1362. doi:https://doi.org/10.1126/science.663616.

Fischer, C. S., Hout, M., Jankowski, M. S., Lucas, S. R., Swidler, A., & Voss, K. (1996). Inequality by design: Cracking the Bell Curve myth. Princeton: Princeton University Press.

Freeden, M. (1979). Eugenics and progressive thought: A study in ideological affinity. The Historical Journal, 22(3), 645-671. doi:https://doi.org/10.1017/S0018246X00017027.

Hyytinen, A., Ilmakunnas, P., Johansson, E., & Toivanen, O. (2019). Heritability of lifetime earnings. The Journal of Economic Inequality, 17, 319–335. doi:https://doi.org/10.1007/s10888-019-09413-x.

Ioannidis, J. P. A. (2005). Why most published research findings are false. PLOS Medicine, 2(8), e124. doi:https://doi.org/10.1371/journal.pmed.0020124.

Justman, M., & Gilboa, Y. (2012). The scope for promoting equal opportunity in education: Evidence from the Kibbutz. Education Finance and Policy, 7(4), 489-515. doi:https://doi.org10.1162/EDFP_a_00077.

Kitschelt, H. P., & Rehm, P. (2022). Polarity reversal: The socioeconomic reconfiguration of partisan support in knowledge societies. Politics & Society, 0(0), 00323292221100220. doi:https://doi.org/10.1177/00323292221100220.

Kuhn, T. S. (1962/1996). The structure of scientific revolutions (Third ed.). Chicago: University of Chicago Press.

Marks, G. N. (2022). Cognitive ability has powerful, widespread and robust effects on social stratification: Evidence from the 1979 and 1997 US National Longitudinal Surveys of Youth. Intelligence, 94, 101686. doi:https://doi.org/10.1016/j.intell.2022.101686.

Marks, G. N., & O'Connell, M. (2021). Inadequacies in the SES–achievement model: Evidence from PISA and other studies. Review of Education, 9(3), e3293. doi:https://doi.org/10.1002/rev3.3293.

Marks, G. N., & O’Connell, M. (2023). The importance of parental ability for cognitive ability and student achievement: Implications for social stratification theory and practice. Research in Social Stratification and Mobility, 83(February), 100762. doi:https://doi.org/10.1016/j.rssm.2023.100762.

Paul, D. (1984). Eugenics and the left. Journal of the History of Ideas, 45(4), 567-590. doi:https://doi.org/10.2307/2709374.

Plomin, R., & Deary, I. J. (2015). Genetics and intelligence differences: Five special findings. Molecular Psychiatry, 20(1), 98–108. doi:https://10.1038/mp.2014.105.

Pokropek, A., & Sikora, J. (2015). Heritability, family, school and academic achievement in adolescence. Social Science Research, 53(September), 73-88. doi:http://dx.doi.org/10.1016/j.ssresearch.2015.05.005.

Richardson, K. (2002). What IQ tests test. Theory and Psychology, 12(3), 283-314. doi:https://10.1177/0959354302012003012.

Ritzer, G. (1975). Sociology: A multiple paradigm science. The American Sociologist, 10(3), 156-167. Retrieved from http://www.jstor.org/stable/27702185.

Sesardić, N. (2005). Making sense of heritability. Cambridge: Cambridge University Press.

Silventoinen, K., Jelenkovic, A., Sund, R., Latvala, A., Honda, C., Inui, F., . . . Kaprio, J. (2020). Genetic and environmental variation in educational attainment: An individual-based analysis of 28 twin cohorts. Scientific Reports, 10(1), 12681. doi:https://doi.org/10.1038/s41598-020-69526-6.

Warne, R. T. (2020). In the know: Debunking 35 myths about human intelligence. New York: Cambridge University Press.

Aporia

Death of a Paradigm