Following the Nobel prize-winning discovery of the structure of DNA in 1953, immense advances have been and continue to be made in our understanding of the structure and function of DNA and of how the genes encoded in it work. Alongside and bound up with this have been advances in our understanding of heredity.
Some of what we have learned has encouraged Christians by supporting the Bible’s teaching. Most obviously, genetic studies have proven not just that men and women have different chromosomes, but that established sex differences in physiology and psychology are driven by genetic differences. Yes, contrary to many current arguments, men and women are fundamentally different! But other genetic discoveries have made Christians uncomfortable, indicating that key aspects of our beliefs and behaviour are also driven by our genes.
We recoil from the uncomfortable idea that our decisions and our everyday behaviours, even our personalities, even our faith, are all written in our genes.
Genetic studies of intelligence have long made people uncomfortable. Various measures of intelligence, IQ tests, have shown that intelligence is about 50–60 per cent inherited. Interestingly, studies showing a similar level of heredity for height have never excited much of a reaction. The rationale seems to be that no one worries about genes determining our height but we like to believe our intelligence is free and can be improved by education and training.