British and American children who are less intelligent are more likely to grow up to be conservative and/or bigots, according to new research published in Physiological Science.

The research study, "Bright minds and dark attitudes", used data from two British studies that tested the intelligence of children born in 1958 and 1970. The tests were carried out when the children were around 10 years old, and then when they reached their 30s the subjects were quizzed on their political views. Data was also used from a similar study in the US, where attitudes towards homosexuality were checked.

“We found that lower general intelligence in childhood predicts greater racism in adulthood, and this effect was largely mediated via conservative ideology,” said Professor Gordon Hodson, a psychologist at Brock University in Ontario. “A secondary analysis of a US data set confirmed a predictive effect of poor abstract-reasoning skills on antihomosexual prejudice, a relation partially mediated by both authoritarianism and low levels of intergroup contact.”

Over 15,000 subjects were asked a series of questions to gauge their political views and attitudes towards race and homosexuality, such as "Family life suffers if mum is working full-time," and "I wouldn't mind working with people from other races."

In the British study, 62 per cent of boys and 65 per cent of girls whose level of intelligence was below the median at age 10 expressed above-median levels of racism during adulthood. Conversely, only 35 to 38 per cent of the children with above-median levels of intelligence exhibited racist attitudes as adults.

The team stress these results are based around median levels, meaning there are plenty of smart racists and tolerant thick people. But on average there was a clearly defined link between sub-par cognitive skills and abstract reasoning and bigotry.

“Cognitive ability is a reliable predictor of prejudice. Understanding the causes of intergroup bias is the first step toward ultimately addressing social inequalities and negativity toward out-groups. Exposing right-wing conservative ideology and intergroup contact as mechanisms through which personal intelligence may influence prejudice represents a fundamental advance in developing such an understanding,” the paper concludes. ®