London- An international team of researchers has discovered 40 genes linked to human intelligence.
The researchers led by Danielle Posthuma from Amsterdam University said they reached this conclusion after collecting data from different researches conducted on 60,000 adults and 20,000 children in Europe.
The study published in Nature Genetics magazine reported genetic factors in humans are responsible for determining intelligence by 45 percent in childhood, and up to 80 percent in adulthood.
According to researchers, those genetic factors include not only genes, but also tiny changes in the DNA’s components known as single nucleotide polymorphisms (SNP).
They pointed out that intelligence differences between people can be explained through the genetic factors, and that most of the hereditary genes play a major role in the brain- a role that resemble the nervous cells’ creation process.
They added that intelligence genes have been linked to positive results including academic success, quitting smoking, brain size during childhood, autism, body size, and life expectancy. However, they have been also linked to negative outcomes such as Alzheimer, depression, schizophrenia, hyperactivity, smoking, and anxiety.
Other researchers, including Rainer Riemann from the University of Bielefeld, assume that intelligence is a hereditary characteristic in 40 percent of children and 60 percent of adults.
He said: “Today, we know that the genes associated with intelligence do not give the expected results simply, yet, a stimulating environment is necessary for this purpose”.
The study also shows that intelligence is an important but not sufficient condition to have good school grades; a child with regular capacities has big chances for a good school performance if he studies seriously.
Elsbeth Stern of the Swiss Federal Institute of Technology Zurich said determining intelligence level in humans by reading their genes is not a distressing thing, but intelligence is also subject to the entourage’s influence. She asserted that hereditary characteristics cannot give the expected results without stimulating conditions.