Published on March 21st, 20130
Children’s intelligence written in genes
On average, between 20 and 40% of a child’s intelligence is inherited, found an international team of researchers.
Benyamin argues that previous studies performed on twins and families suggest that genes may be responsible for 40% of childhood intelligence. But he also believes that such conclusions are controversial because it is impossible to separate environmental factors.
“In our study we found that between 20 and 40 percent of the variation in IQ in childhood are caused by genetic factors“, said study coordinator for. Beben Benyamin, University of Queensland.
To counter these limitations of studies conducted on families, Benyamin used genetic information in Australia, UK, Netherlands and USA. More specifically, he coordinated team analyzed DNA samples and IQ test results from nearly 18,000 children aged between 6 and 18 years. Through this experiment, scientists wanted to know if I can correlate patterns of DNA differences with those of IQ.
Thus, they discovered that a gene called FNBP1L, previously known as a gene significantly associated with adult intelligence was strongly associated with childhood intelligence.
But when researchers seeking genetic factors influencing intelligence and other traits, they prefer to look uninucleotidic polymorphisms (SNPs) or gene variants that provide accurate genetic information.
Just as with similar studies conducted in adults, researchers found no genetic variant SNP that is strongly associated with childhood intelligence.
“But when I looked at the combined effect of all SNPs we could estimate the genetic contribution to be 20% - 40% of the difference in IQ“, said Benyamin.
Experts explained that the new study estimates are lower than those resulting from studies conducted on families and twins, and this might be because were analyzed only the common SNPs.
Benyamin argues that many genes contribute to intelligence from childhood and each one provides a small effect.
Sursa: ABC News