Intelligence really is in our genes, study shows

Scientists have known for some time that there are many genetic and environmental factors that contribute to a person's intelligence.

Now, researchers from King's College London have discovered a particular gene that may explain intellectual differences in teenagers and further contribute to our understanding of learning disabilities, reports Reuters.

The team of scientists found that a mutation in the NPTN gene is linked to thinner "grey matter" in the brains of teenagers who consequently received lower scores on intellectual tests.

Grey matter refers to the cerebral cortex region of the brain, which is related to our ability to remember, pay attention and think. It also plays a key role in perceptual awareness, language and consciousness.

"We wanted to find out how structural differences in the brain relate to differences in intellectual ability," explains lead author Sylvane Desrivières.

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The study, published in the journal Molecular Psychiatry, gave verbal and non-verbal intelligence tests to more than 1,500 healthy 14-year-olds.

After analyzing more than 54,000 possible genetic variants involved in brain development, the researchers discovered that teens with a low-functioning NPTN gene had a thinner cerebral cortex in the left half of their brains. These same teens also received the lowest scores on the intellectual tests.

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"It's important to point out that intelligence is influenced by many genetic and environmental factors. The gene we identified only explains a tiny proportion of the differences in intellectual ability," Desrivières notes.

The researchers hope their findings can provide insight into the biology behind learning disabilities as well as psychiatric disorders, such as autism and schizophrenia.