• Question: Are there specific genes for intelligence? @swbgs

    Asked by Borlasian to Barbara, Matt, Ravinder, Sophie, Tristan on 6 Mar 2015.
    • Photo: Matthew Moore

      Matthew Moore answered on 6 Mar 2015:

      Great question!

      Broadly, traits tend to be ‘continuous’ or ‘discontinuous’, all that means is that eye colour, for example, is controlled by one gene and you either have blue or brown or green eyes etc –it’s discontinuous, one or the other and is not affected by the environment. Height on the other hand is continuous, you’re not either short or tall, you’re anywhere between really short and really tall, a spectrum.

      First of all with intelligence, it’s incredibly difficult to measure! Who is smarter a theoretical physicist or a football player? A person who is very good at using mathematics to unravel what happened at the start of the universe wouldn’t necessarily be able to consider all of the plays available on a football pitch and make the best decisions about where to be when the ball is crossed!

      Broadly speaking however, intelligence (let’s say IQ results) is a ‘continuous’ trait. You’re not of either low or high IQ, but rather anywhere from really low to really high. When traits are continuous they are controlled by loads of different genes, this makes it really hard to determine how much your genes contribute to your intelligence (especially as these same genes which appear to be involved in intelligence, will have other purposes too).

      To make matters more complicated, intelligence, being continuous and therefore controlled by lots of genes that are involved in lots of other things means that it’s heavily influenced by the environment. Obviously, if you study lots then you’ll be ‘smarter’.

      In summary, there aren’t exactly specific genes, which make you smart or not, but rather there are an interplay between a collection of genes and your environment (nature vs nuture). How much your genes contribute to your intelligence is very difficult to work out, it could be most environment or not!

    • Photo: Sophie Robinson

      Sophie Robinson answered on 10 Mar 2015:

      Intelligence is thought to be what’s called a multi-factorial trait. That means it is controlled not by just one or a few genes, but by many genes as well as the environment.

      So yes, some people may have versions of genes that make them more intelligent than others. However environment will also have an impact too. For instance if you were surrounded by lots of educational books and toys when you were young, you may be more intelligent than someone that wasn’t. Also, if you study harder, your brain cells will develop in a certain way meaning you may find it easier to understand things than someone that doesn’t study does.

    • Photo: Barbara Shih

      Barbara Shih answered on 12 Mar 2015:

      It’s an interesting topic. Scientists have been trying to find the “intellegence” gene. Twin studies repeated suggests that genes are involved in intelligence (done by comparing either identical twins of non-identical twins- both sets of twins should have similar upbringing, but the identical twins would have the same genes).

      However, although a recent large genetic study have pin-pointed some genetic differences related to higher IQ score, having one of these “smart gene” would only contribute to 0.3 points in IQ test. This does not explain the differences we see in IQ results in people. http://www.nature.com/news/smart-genes-prove-elusive-1.15858

      What’s more, like what Matt has said, it’s difficult to say what is intelligence. Here is a video about a small test they did on a group of people. https://www.youtube.com/watch?v=jW8qF3tUDl8
      As expected, the theoretical physicist was very good at IQ test. However, when the physicist was challenged by glasses that turns his vision up-side-down, he could barely move, whereas the artist quickly adapedt to this new set of “rules” relating what she saw to her own body.

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