Thomson has published papers on a variety of issues, including racism, narcissistic personality disorder, forensic psychiatry, depression and PTSD, and has written psychobiographical essays on Lee Harvey Oswald and Robert E. Lee. He is most noted for his work on evolutionary psychology, as well as for his exploration of the cognitive and evolutionary basis of religious belief, as presented in his latest book entitled Why We Believe in God(s): A Concise Guide to the Science of Faith. Dr. Thomson has been a featured speaker at several atheist conferences including American Atheists 2009 and Atheist Alliance International 2009 for which he spoke about his theories on the cognitive origins of religious belief. In an interview with the Austin American-Statesman, Thomson stated, "There is a massive, irreconcilable conflict between science and religion. Religion was humanity's original cosmology, biology and anthropology. It provided explanations for the origin of the world, life and humans. Science now gives us increasingly complete explanations for those big three."