My personal theory is that psychologists are more likely to reject dualism, since they have a unique understanding of how the mind is essentially inseparable from the brain. Hence, they are more likely to be materialists and reject supernatural explanations for consciousness.
Fifty percent of professors of psychology at US universities and colleges do not believe in any god, and another 11% are agnostic. That makes them the least religious of a pretty heathen bunch.
The data come from Politics of the American Professoriate study, a survey carried out in the spring of 2006 and published yesterday in the journal Sociology of Religion. The researchers, Neil Gross of the University of British Columbia and Solon Simmons of George Mason University, surveyed nearly 1500 full-time college and university professors teaching in U.S. institutions.
The results are reminiscent of a 2007 survey which found that psychiatrists were the least religious of physicians. It seems that there's something about studying how the mind works that makes people skeptical of the God delusion!
Gross and Simmons looked into the link between academic field and religion in some detail. Here's what they concluded
With other factors controlled, biologists and psychologists—relative to professors outside the top 20 fields—are less likely to believe in God and less likely to hold traditional views of the Bible; professors of communications, English, and history are less likely to hold traditional views of the Bible; sociologists are less likely to have a traditionalistic religious orientation overall; and professors of accounting, finance, and nursing tend to be more religious.