Are we getting smarter?

Hello everyone, sorry for the lack of blogging over the last month or so – I’ve been doing some extra work in my free time which I’m sure I’ll share on here once it’s published! But I’ve got a bit of a break between deadlines, so I’m back with this post about intelligence and IQ tests which will aim to answer the question: are we getting smarter?

Let’s start off with a bit about IQ tests. There are several which are regularly used in scientific research, such as Raven’s matrices, the Weschler Intelligence Scales, and the Stanford-Binet Intelligence Scale. See how you get on with these example questions and scroll to the bottom for answers!

Raven’s Matrices:

This is a progressive IQ test, with questions becoming harder as you progress through the test. Easier questions at the beginning are used to test children – I’ve done used this before for a research project and it’s relatively simple to explain meaning young children can’t be confused by long written instructions. It is a non-verbal test made of 60 multiple choice questions which measures ‘fluid intelligence’ – or reasoning. Participants are shown a geometric design with a missing piece, and have to choose from multiple options which piece fits best. Have a go at these and see how you get on..

a)

RAPM2

b)

RAPM31

Weschler Adult Intelligence Scale

This test measures cognitive abilities, with the most recent edition – the WAIS-IV, including 4 IQ sub scales: Verbal comprehension, Perceptual reasoning, Working memory and Processing speed. Like the Raven’s matrices, this scale has been adapted for use with children and is also used in a clinical setting, for example when testing for developmental disorders or dementia. See an example below:

c)WAIS-IV_Visual_Puzzles

So how did you get on? Composite scores from answering all of the questions in these intelligence tests are combined to give a score of Intelligence Quotient, or IQ. IQ tests such as the ones above are developed to give a median score of 100 with each standard deviation of 15 IQ points. This is often illustrated in a bell curve, as shown below:

bell-curve-normal-distribution-iq

But are we getting smarter? A scientist called James Flynn has documented the fact that as a population, we are performing better at IQ tests over time. This has therefore become known as the Flynn Effect. Using Weschler tests, it has been estimated that IQ increases by about 3 points per decade. IQ tests such as these have undergone several revisions over time (the first Weschler test was developed in 1939), and scores are standardised using testers to give a median of 100. When these new test subjects take the older versions of the test, they usually score significantly higher than 100, implying our intelligence is increasing. Possible explanations for this increase include better schooling, better nutrition and health. However, there is some debate about whether people are really  getting more intelligent, or are just getting better at taking intelligence tests!

Thanks for reading, I hope you enjoyed this post. I should be back to regular uploads soon!

Answers: a) 3, b) 8, c)1,3,6.

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