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The age-old nature versus nurture argument is never far from the forefront of debate. Why do good people sometimes produce evil offspring? How can siblings be so different despite having the same parents and similar upbringings? This same conundrum surrounds intelligence. There is no definitive answer to why someone who inherits genes may not inherit the same level of intelligence as their predecessors. The common answer is to reason that people are result of a mixture of both nature and nurture.

IQ genes

Now, scientists have taken the theory of genetic intelligence a step further by identifying more than 500 genes that they associate with intelligence that they refer to as IQ genes — more than ten times the amount previously identified. The researchers also made an association between these IQ genes and life expectancy. 

Previous studies have shown that people with higher cognitive and physical health send stronger signals between different regions of the brain and are more protected from conditions such as Alzheimer’s. People with higher cognitive abilities are also less likely to suffer from premature death.

The study, which was published in the journal, Molecular Psychiatry, looked at DNA variations in more than 240,000 people in different countries. The gene samples, which were taken from the UK Biobank, were then compared to people’s IQ scores, which were based on numerical and verbal tests.

The researchers identified 187 regions of the participant’s genomes that are associated with thinking skills as well as 538 genes involved in the processes. 
The new findings raised the possibility that in future, it may be possible to assess people’s intelligence using simple DNA saliva tests.