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.

Face Illusion

Hi everyone,

I haven’t done a Brainteaser for a while, so I thought I’d share with you this clip from QI to see how you get on!

 

What you should notice, is that when the face is pointed towards you, it appears to be 3D and facing you, regardless of whether or not you are seeing the concave side of the image or not.

This illusion is known as ‘cognitively impenetrable’ because no matter how hard we try to see the face as pointing away from us, our brain always shows us the opposite – in this illusion having knowledge of how it works does not affect it at all.

This therefore shows how powerful the illusion is, and as Stephen Fry mentions in the clip, it shows how automatically we perceive faces, and how biased we are to perceive stimuli as faces. (For more information on this topic, check out my post here)

He also mentions that this ability is thought to be innate – babies only a few hours old have shown to prefer to look at images of faces rather than other stimuli (e.g. Batki et al 2000) and look at whole faces, rather than faces with scrambled features (but otherwise identical) e.g Goren et al (1975).

These results show that infants must have some sort of knowledge about faces and social interactions when they enter the world. Further evidence to support this is shown in a famous study by Meltzoff & Moore (1977) in which young infants – only a few weeks old were about to imitate facial expressions – shown in the well-known image below. This shows how important social interactions are to us at such a young age, as they provide the basis for our further development.

Classic77 Meltzoff_legend (3)

 

 

Patience and rewards – the ‘raisin test’

This week’s post is about a study carried out at the University of Warwick which has been in the news recently, in which they were able to predict a child’s intelligence as they grew older using a simple test with a raisin.

In this test, a raisin was covered with a cup, and put in front of the young children who took part. They were told they had to wait for a minute until they could eat the raisin.

Results showed that children who were born prematurely were more likely to eat the raisin without waiting for the minute to elapse, and that the children who were more impatient did not perform as well in school when they were older – aged 8 (Wolke et al).

This method tests for something called ‘inhibitory control’ and is a cognitive skill learnt during childhood and is linked to activity in the prefrontal cortex. It is often disrupted in children with ADHD.

It is a similar method to the well known ‘Stanford Marshmallow Test’, in which children were told they could eat one marshmallow now, or wait for 15 minutes and have two. This research was carried out by Walter Mischel, who followed up on his original study to see how successful the original participants were during adulthood. This also found a correlation between those who were able to wait for the reward, and future successes.

marshmallow-test

Mischel believed that some children were able to wait for the larger reward because they were capable of more abstract thinking, and could picture the reward occurring. The fact that executive function performance during childhood can predict later achievements is fascinating, although of course it is not the only factor.

So, would you like one marshmallow now?

The Strange Situation

Something related to developmental psychology now – in particular, how do we know if an infant is securely attached to their parent? Attachment means the emotional bond that connects one person to another (Ainsworth). If  attachment is successful, then there is a secure bond between the infant and their parent, which is thought to lead to psychological and social benefits to the child as they grow up, e.g. being better at expressing emotions and better social skills. So let’s start with the basics, what are the types of attachment?

As mentioned above, if attachment is successful, then it is said to be secure. There are two different forms of insecure attachment: insecure/avoidant, and insecure/resistant. These represent the opposite ends of insecure attachment: infants with resistant type are more clingy to their caregivers, whilst avoidant children tend to seek less interaction and avoid new situations.

This leads us nicely into an important question.. how can we measure attachment? Mary Ainsworth (1969) devised an assessment called the Strange Situation: a mother and her baby came to a lab and took part in an observed experiment. There are 8 stages in total, and these are shown in the table below:

strange_situation1320259450389

As you can see, the infant’s behaviour was monitored throughout this situation, and was then categorised into the 3 attachment types. The table below summarises their results:

2199544

As you can see, infants with a secure attachment cope better being left in an unfamiliar environment – they are less anxious as they know their mother will return. As well as these results, Ainsworth & Bell (1970) found that infants with a secure attachment are more likely to have a mother who is sensitive to their needs e.g. comfort them when they cry. This secure attachment provides a basis for the infant’s social relationships as they grow older, so is strongly encouraged.

If you would like to see a video of the strange situation in action then click here!