The average intelligence of the human race has been steadily increasing, scientists have claimed. In research looking back over IQ tests from the past few decades, they found that the tests were becoming harder - but people were still doing just as well. But the reasons why people are becoming smarter is not known - with theories including better education and improved medical care. Researchers at Kings College London looked at scores over 64 years. In total, more than 200,000 participants in IQ tests were studied. Since 1950, average intelligence was found to have risen by about 20 IQ points. Explanations include better education (stock image shown) and improved medical care . The research, titled A Cross-Temporal Meta-Analysis of Raven's Progressive Matrices and reported by William Kremer for the BBC, was published in the journal intelligence. Carried out by Peera Wongupparaj, Veena Kumari and Robin Morris from Kings College London, they looked specifically at the Raven’s Progressive Matrices (RPM). Poverty affects the intelligence of children as young as two, a separate study in December 2014 found - and its impact increases as the child ages. Deprived young children were found to have IQ scores six points lower, on average, than children from wealthier families. And the gap got wider throughout childhood, with the early difference tripling by the time the children reached adolescence. Scientists from Goldsmiths, University of London compared data on almost 15,000 children and their parents as part of the Twins Early Development Study (Teds). The study is an on-going investigation socio-economic and genetic links to intelligence. This tasks participants with looking for patterns in an array of shapes - and is thought to be a good measure of intelligence. In total, more than 200,000 participants from 48 countries over 64 years were studied in the research. Since 1950, it was found that the average intelligence had risen by the equivalent of 20 IQ points. 'RPM is a valid and reliable measure of general IQ, Dr Wongupparaj told MailOnline. 'Also, it is cultural-free test so that it has been widely used for nearly 80 years.' ‘IQ tests are designed to ensure that the average result is always 100, so this is a significant jump,’ the BBC reported. The research builds on earlier evidence from philosopher and psychologist James Flynn, from the University of Otaga in New Zealand. He had noticed that IQ tests were getting harder, but people were still getting similar scores on them - which became known as the Flynn Effect. This graph shows how the Raven’s Progressive Matrices (RPM) scores have been increasing over time. RPM is seen as an accurate way of measuring intelligence, and 'it is cultural-free test so that has been widely used for nearly 80 years,' Dr Wongupparaj told MailOnline . The research was carried out by scientists from Kings College London. They looked specifically at the Raven’s Progressive Matrices (RPM) - an example is shown. This tasks participants with looking for patterns in an array of shapes - and is thought to be a good measure of intelligence . Apparently, if modern Americans took a test from a century ago, they would get a relatively high average IQ score of 130; vice versa, and our ancestors would score a measly average of 70. This equates to a three-point rise in IQ per decade. According to the new study, though, outside of the US the biggest change was clearly in developing countries, IQ was ‘catching up with the developed world’. ‘There are multiple possible reasons proposed for this phenomenon,’ they write. These include improved education, increased exposure to testing, improved medical care and nutritition and decreased family size. Perhaps most importantly, though, is that the instance of IQ increasing was not just true in general for the world as a whole - but could also be noticed on a much smaller scale. ‘The Flynn effect is strong enough to be showed in even small and non-representative samples as well as in the very young and older adults,’ the researchers conclude.
Researchers at Kings College London looked at scored over 64 years . In total, more than 200,000 participants in IQ tests were studied . Since 1950, average intelligence was found to rise by about 20 IQ points . Explanations include better education and improved medical care .