Why Life in the Womb May Determine Your Baby's IQ
Charles Arthur Science Editor, The Independent (London, England)
The environment of the womb plays a significant part in determining a child's future intelligence, according to research published today. It also suggests genetic effects are frequently overstated in arguments about IQ, and that pregnant women can enhance their child's potential intelligence by avoiding toxins and living healthily.
The work, which pulls together studies on 50,470 twins from 212 different IQ studies, is published today in the Nature journal. By statistical analysis, it quashes the idea that genes determine intelligence more than environment does - that is, that nature overwhelms nurture.
The work, led by Bernard Devlin, of the University of Pittsburgh, Pennsylvania, analysed the fact that the similarity in IQ between a pair of twins is not easily accounted for by their shared genes and living environment. Identical twins have identical sets of genes, and often identical rearing. Non-identical twins have the different genes, but the same rearing. Siblings have different genes and, generally, different rearing. When data was analysed about the IQ similarity of non-twin siblings reared apart, as well as twins reared apart, variations in IQ appeared that could not be accounted for by genes or home environment. In the case of similarity between twins this amounted to 20 per cent, and in the case of non-twin siblings 5 per cent. The only explanation was the effect of what happened to the foetus in the womb. …