Medical Interventions for Cognitive Impairment

Abstract

We have proposed that the Flynn effect – the progressive rise in IQ that is well documented over the past several decades – may have arisen because of successful intervention into medical conditions that depressed intelligence in the past. In the United States alone, more than 10 million children are at risk from the effects of poverty, and the average number of IQ points potentially lost to poverty is about 4. This means that 41.7 million IQ points may be at risk from the effects of poverty. Across the 30 conditions identified as problematic in the United States, the average IQ loss is about 9 points. Hence, the aggregate number of IQ points lost to a remediable medical challenge in the United States is about 389 million points. If there are 74 million young people in the United States, then an average of more than 5 IQ points are at risk per person. However awful this is, it was almost certainly worse in the past. A child blessed with genes that could confer intelligence will not actually have a high IQ unless that child has a fairly benign medical environment. In the absence of disease, children can fulfill the promise of their genes; but disease can prevent a child from achieving her full potential, no matter how favorable her genes. Genes determine the potential, whereas environment determines the actual. In a sense, genes determine the range through which environment can modify an individual. Favorable genes and a benign environment may enable a child to reach her full genetic potential. But favorable genes and a malign environment may provide no better outcome for a child than would unfavorable genes. This forces us to consider a question relevant to millions of children who have perhaps already suffered a poor outcome from poverty or other remediable medical event.