Sunday, February 1, 2009

Facts about IQ

If you ask people how intelligent they think they are it is interesting to know that the average perception is that everybody thinks they are above average. This is also true for the self-perception of how good one looks. Everybody thinks they are better looking then they actually are. One group gets it right though and that is the depressed people. They have an accurate assessment of how intelligent or good looking they are. Some have said that our unreal perception of our intelligence keeps us from being depressed!

We can divide the intuitive idea of intelligence in the following ways:
1. Fluid intelligence: Set of reasoning abilities that let you deal with abstract relations which reaches its mature state by age 16.
2. Crystalline intelligence: Application of knowledge to particular tasks. This ability keeps growing throughout our life span. Example vocabulary.

IQ tests measure fluid intelligence! A simple test of fluid intelligence is one which involves “number calculation + remembering a word”. Example if the tester were to say “4+3-1=?, Uncle” I would have to do the calculation and remember the word. The calculation would then became harder example “23-16+4=?,fish” and I would have to remember the word again. The more I am able to stretch myself the better my IQ would be!

Intelligence is a good predictor of
1. School performance
2. Higher lifetime salary
3. Less of a chance of a criminal conviction
4. Less of a chance of teen pregnancy

In a population the variance in IQ comes from the variance due to genetic factors and the variance due to environmental factors. However what is more important than both factors is the “interaction term” which is the cumulative effect of the two. For example in a socio-economic environment where resources are low the environment may be such that one’s fluid intelligence is not able to hit its peak! One evidence for this is before WW II the Japanese IQ was 10 points lower than the US and after WW II it was 10 points higher!

In fact all over the world IQ has been getting higher. IQ is improving too fast for it to be genetic.

This leads to policy implications as follows. The state should give the poor resources so that they can develop good IQ. If they do this the chances that they will end up in crimes or get pregnant will be reduced and this will benefit the whole of society.

An experiment was done where children of a low SEC (socio-economic-class) were given good resources and did as well as the students from higher SEC but as they grew older they started doing poorly again! One could argue that the experiment failed and it was much like the rubber-band effect where they snapped back to their original. However one would argue that you should never let the rubber band snap back much like the medication that is given to diabetes patients which is given as long as it is needed.

Another interesting factoid is that while larger brain sizes are generally associated with higher intelligence there have been people with small brain sizes who were very intelligent as well. Example Gauss who made a number of discoveries had a small brain (he came up with the Gaussian curve among other things). However he had a lot of wrinkles in his brain! It is also these wrinkles that are highly associated with intelligence. A dolphin has a larger brain than man but much fewer wrinkles in it for example.

Source: MIT Open Courseware, Introduction to psychology lecture on “Intelligence”

No comments:

Post a Comment