Russell Coker <russell@coker.com.au> wrote:
There are biological factors for impulse control that are well known. The correlation between lead in the bloodstream and poor impulse control is shown by the drop in crime ~20 years after unleaded petrol was introduced.
Fascinating.
For intelligence it's not so clear, while there are obvious biological factors that cause low intelligence (EG fetal alcohol syndrome) it's not clear that there is anything significant we can do to improve things. However the link between intelligence (as measured by IQ tests) and parenting/environment is clear.
I've heard it claimed that the average scores on IQ tests have increased over time, in certain countries, well beyond anything that could be explained biologically; but I haven't read any literature to confirm or dispute this finding. I think the idea for human enhancement of intelligence, though, would be to increase IQ biologically if appropriate means (genetic selection of children, gene therapy, drugs or whatever) were avilable.