Divide and rule – the psychology of capitalism

This week as I am starting on my first assignment for Psychology, I have been learning about the history of intelligence testing and the dark side of psychology history.

In the late 19th century, most psychologists were of the opinion intelligence was inherently fixed and determined by class, gender and race. The first attempts to measure intelligence was done by measuring the size of people’s heads. The results often contradicted the general opinion, as children with big heads sometimes had a lower intelligence than children with small heads, or the results were too close to each other. Not only used these ‘craniometrists’ the measurements to compare individuals, but also whole groups. As Byford et al. (2014) remarks:

“The claim that races, classes and genders differ in intelligence, in a way that always places the privileged groups on top and presents them as ‘superior’, was used to portray the existing social divisions and hierarchies as ‘natural’ and unchangeable”.

They used their biased methods to compare different genders, ethnic groups and social classes and regularly came to conclusions that strengthened divisions, inequalities and discrimination in society at the time (Byford et al., 2014, p. 24). Late 19th, early 20th century Howard Knox introduced a rough intelligence test to the 12 million immigrants arriving in New York between 1892 and 1924, which were screened on a long list of disabilities and conditions which made people ineligible to live in the country, including the mentally unfit (Byford et al., 2014, p.49).

Then in 1917, when the war broke out between Germany and the US, another psychologist named Yerkes developed a mass intelligence test to ‘make the army more effective’ by screening out the least intelligent. The conclusions he drew from it were dual:

  • Median intelligence of the US population was lower than expected. The average US soldier performed on the level of a 13-year old.
  • The results of the test showed obvious ranking in social groups. The rich were more intelligent than the poor, white people more than the Afro-Americans and under immigrants North-Western-Europeans were more intelligent than Eastern or Southern Europeans.

Strangely, Yerkes himself pointed out some much more obvious conclusions from the army test:

  • The longer a person received education, the better they did in the test.
  • Poverty diseases like hookworm were more prevalent under people who did poorly on the army test.
  • Among immigrant recruits there was a strong link between how long they had been in the US before taking the test and their test result.

These conclusions suggest that ‘intelligence’ as measured by the army test was closely linked to education, instead of heritability and therefore inherently biased. But Yerkes decided to ignore these obvious conclusions and give credibility and status to the racist anti-immigrant discourse at the time. Sadly many scientists like Yerkes used these outcomes to strengthen the arguments for eugenics (Banyard, P. 2014, p. 43-78).

And these ways of thinking played right into the hands of capitalists who could use it to justify exploitation of workers, discrimination and division, and capitalise on it. And as a result people with learning disabilities or mental health conditions, as well as physically disabled people were thrown on the scrap heap. Today we see the same happening, but more concealed in cuts to care and mental health budgets, benefit policy and privatisation of public services. But ultimately the result is the same; social division, discrimination and marginalising the poor, the weak, and ethnic minorities.

As these groups are less economically profitable for capitalists, they are no longer regarded a commodity, but a burden on society. Still, every last penny those marginalised and criminalised groups have is squeezed out and taken, and their lives made a misery full of suffering and early death.

Photo credit and link to accompanying article
Photo credit: Paul Mattson (The Socialist, 2021)


Byford J. (2014) ‘Measuring Intelligence’, in McAvoy, J. Banyard, P. (eds.) Investigating Intelligence. Oxford: Oxford University Press/Milton Keynes: The Open University, p. 11-42.

Banyard, P. (2014) ‘Explaining differences in intelligence’, in Byford J. McAvoy, J. (eds.) Investigating Intelligence. Oxford: Oxford University Press/Milton Keynes: The Open University, p.43-78.

Published by Gif-Art

Follow androgynous blogger, poet, artist, Criminology & Psychology scholar and revolutionary socialist Kahlo on their journey of self expression, transitioning and development. They write about Criminology & Psychology subjects in a socialist context, rehabilitation and recovery of childhood trauma, domestic and sexual abuse and the mental health conditions as a result. Woven through is a strong sense of social justice, accountability and self-determination.

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