In this chapter, I turn to the related questions of how and why religion has evolved, and what genetic influence there has been on religion. They have both been lively areas in the study of religion in recent years. I begin with genetics, as it is the more empirical of the two topics, and what you conclude about the genetic basis of religion influences where you stand on some of the debates about the evolutionary basis of religion.

Genetics of Religion

The investigation of the genetic basis of religion is an interesting and complex matter. It is still somewhat inconclusive, despite recent progress. To anticipate my conclusions, it seems likely that some genetic influences are relevant to religion. However, it is doubtful whether there is any genetic basis for religiousness as such, as a unitary package. There is probably more genetic influence on some aspects of religion than others. Also, the most significant genetic influences relevant to religion probably influence a broader range of things, not just religion.

The most widely publicized claim for the genetic basis of religion was made in Dean Hamer's book, The God Gene: How Faith Is Hardwired Into Our Genes (Hamer, 2004). Even if genes influence religiosity, the title is thoroughly misleading. First, genetic influence usually arises from multiple sites in the DNA, not from a single gene. No satisfactory evidence exists for a single “God gene,” and it is highly improbable that there would be one. Second, to talk of faith being “hardwired” implies a simplistic genetic determinism in which genes alone are supposed to control faith. Debate continues about how strong genetic influence on religion might be, but religion is certainly not controlled by our genes. At best, there is genetic influence on religion, not determination.

In discussing this, we also have to take into account radical developments in genetics that have occurred (e.g., Noble, 2006) that have made it problematic to engage in the old project of trying to gauge the relative influence of “nature” and “nurture.” It is now assumed that the interaction between the two is so rich and complex that the distinction between nature and nurture no longer makes any sense.