In your review of some recent research linking religion and diseases you pit Richard Dawkins against other researchers by contrasting his claim that religions are like diseases with their claim that religions stem from the fear of diseases (“Praying for Health,” August 2, 2008). In fact, Dawkins makes little distinction between biological and cultural replicators, or genes and memes, the latter term being of his own coinage. Memes include not only religious ideas, but also symbols, tunes, behavioral patterns, and the like. Like genes, they spread through social contact. Both genes and memes are selfish in the sense that they may replicate to the detriment of individuals and social groups alike. In short, there is no conflict between Dawkins’ ideas and those of the researchers whose work you review. In fact, they support each other rather well.