This is a summary of the talk Prof. Richard Haier gave on September 6 titled The new science of intelligence: men, women and brains. There are various things I do not agree with. However, I will not comment them in this posting to let everybody read what Prof. Haier said and not what I think about what he said.
Contrary to myth, intelligence can be defined and measured. Intelligence tests scores are related to brain features. Genetic and epigenetic influence on intelligence can be assessed: intelligence is thus 100% biological. The talk was organized as follows:
- Examples of people with extraordinary intelligence;
- Measuring intelligence;
- Brain localisation of intelligence;
- Gender-specific intelligence.
Examples of people with extraordinary intelligence
There are striking examples of people with what one may call « an extraordinary intelligence ». For example, Daniel Tammet (a very quick learning of languages and synesthesia), Kim Peek (inspired the movie « Rain man » and has an impressive photography memory), Derek Paravicini (can play any musical piece after hearing it just once), Stephen Wiltshire and of course, Albert Einstein.
An example with Tetris players was also shown where one could see the difference between a naive player (someone who begins playing the game) and an expert player. The difference in performance, therefore in reaction and efficiency was remarkable.
How then do we define intelligence?
According to the APA (American Psychological Association) Task Force, intelligence may be defined as follows: « Individuals differ from one another in their ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, to overcome obstacles by taking thought. ». Psychologists define intelligence as the differences individuals have in the ability to learn, memorize and pay attention.
Whatever the definition is, two facts are clear:
- all of us know that there exists someone who is not as intelligent as we are;
- intelligence has something to do with brain.
IQ scores are fairly stable over time. These scores predict many real-world things such as education level, income, job performance. They do not predict other important things like hapiness, honnesty, etc. There are many tests mmeasuring various mental abilities (e.g., rotating 3D objects in one’s head) and other which relate to general abilities (e.g., memory). Furthermore, after performing and analyzing a great number of tests, we can deduce that different mental abilities are not independant. This is called g and refers to « general intelligence ». One can have specific abilities, but lack g.
Where in the brain is the intelligence?
How does g relate to the brain? In other words, are there separate brain systems for the different types of intelligence?
Twin studies have been performed and discussed a lot in the past years. They give hints to something which can be summarized as « if something is genetic, it must work through biology ».
Tomographies have been performed during the time a person is doing Raven’s progressive matrix resolution. Surprisingly, bad scores correlate with big brain activity and vice-versa. This is somehow logical, though: inteligence is not how hard the brain works, but how efficiently it works.
Is there any difference in brain parts which are ON between men and women when they solve problems? Experiments have been performed with men and women having high and average SAT scores. It was observed that in men, a good correlation between activity in temporal lobes and high scores may be established: the harder the temporal lobes are working, the better the scores. However, no such association was observed in women. There was no relationship between given brain part and solving hard math problems. But these women were performing as good as the men with hard-working temporal lobes.
The voxel-based morphometry allows to calculate gray and white matters amounts as well as CSF amount. What happens if this method is applied to study intelligence? It appears that gray matter is clearly distributed in particular locations which correlate with high IQ. A model called PFIT is established where given areas correspond to active locations correlating with high IQ. The PFIT areas are found to be related to learning, memory and attention. The intelligence could be then defined as how information gets through these particular zones.
It is then interesting to adress the question about gender differences in the IQ/gray matter correlation given that, at equal IQ performances, the brain areas are not the same. Women have more gray matter on average than men; the opposite is true for white matter. Therefore, sexe differences suggest that brain has different ways to accomplish the same mental ability. A paper by Halpern et al. has described gender differences in science and math.
Does a brain become more intelligent with learning? Does gray matter increase after practice? There is no overlap shown between areas from the brain where gray matter increase and efforts decrease.
What about being able to increase one’s IQ? Something like being able to create an IQ Pill: would you take it? A poll has been performed and it comes out that 20% of the people already use some drugs to improve concentration. 70% would risk mild side effects to boost brain power and more than 1/3 would accept that their child takes this treatement if other children do it. According to Prof. Haier, if we assume that more intelligence is better than less, don’t we have the moral obligation to increase it?