Intelligence and Genetics
Is there a genetic basis for intelligence?
Absolutely. Unfortunately, due to the fact that there are over a thousand different genes that go to make up how our minds work, this subject is only just beginning. At the moment (October 2001), genetics is at the stage where they are still working on the diseases where a single gene causes specific health problems.
As the human genome project gets underway, there is just starting to be enough information available to untangle which chemicals certain genes code for. It will be a number of years before this data is sufficient to start the process of understanding the genetic basis of intelligence.
On the other hand, identical twins have identical genes, so using psychometrics, you can identify the differences between the individuals, and you can be sure that the differences are not due to genetics. This gives you a handle on doing psychological investigations of intelligence.