The question of religious belief among US scientists has been debated since early in the century. Our latest survey finds that, among the top natural scientists, disbelief is greater than ever — almost total.
Research on this topic began with the eminent US psychologist James H. Leuba and his landmark survey of 1914. He found that 58% of 1,000 randomly selected US scientists expressed disbelief or doubt in the existence of God, and that this figure rose to near 70% among the 400 “greater” scientists within his sample1. Leuba repeated his survey in somewhat different form 20 years later, and found that these percentages had increased to 67 and 85, respectively2.
In 1996, we repeated Leuba's 1914 survey and reported our results in Nature3. We found little change from 1914 for American scientists generally, with 60.7% expressing disbelief or doubt. This year, we closely imitated the second phase of Leuba's 1914 survey to gauge belief among “greater” scientists, and find the rate of belief lower than ever — a mere 7% of respondents.
Leuba attributed the higher level of disbelief and doubt among “greater” scientists to their “superior knowledge, understanding, and experience”2. Similarly, Oxford University scientist Peter Atkins commented on our 1996 survey, “You clearly can be a scientist and have religious beliefs. But I don't think you can be a real scientist in the deepest sense of the word because they are such alien categories of knowledge.”4 Such comments led us to repeat the second phase of Leuba's study for an up-to-date comparison of the religious beliefs of “greater” and “lesser” scientists.
Our chosen group of “greater” scientists were members of the National Academy of Sciences (NAS). Our survey found near universal rejection of the transcendent by NAS natural scientists. Disbelief in God and immortality among NAS biological scientists was 65.2% and 69.0%, respectively, and among NAS physical scientists it was 79.0% and 76.3%. Most of the rest were agnostics on both issues, with few believers. We found the highest percentage of belief among NAS mathematicians (14.3% in God, 15.0% in immortality). Biological scientists had the lowest rate of belief (5.5% in God, 7.1% in immortality), with physicists and astronomers slightly higher (7.5% in God, 7.5% in immortality). Overall comparison figures for the 1914, 1933 and 1998 surveys appear in Table 1.
Repeating Leuba's methods presented challenges. For his general surveys, he randomly polled scientists listed in the standard reference work, American Men of Science (AMS). We used the current edition. In Leuba's day, AMS editors designated the “great scientists” among their entries, and Leuba used these to identify his “greater” scientists1,2. The AMS no longer makes these designations, so we chose as our “greater” scientists members of the NAS, a status that once assured designation as “great scientists” in the early AMS. Our method surely generated a more elite sample than Leuba's method, which (if the quoted comments by Leuba and Atkins are correct) may explain the extremely low level of belief among our respondents.
For the 1914 survey, Leuba mailed his brief questionnaire to a random sample of 400 AMS “great scientists”. It asked about the respondent's belief in “a God in intellectual and affective communication with humankind” and in “personal immortality”. Respondents had the options of affirming belief, disbelief or agnosticism on each question1. Our survey contained precisely the same questions and also asked for anonymous responses.
Leuba sent the 1914 survey to 400 “biological and physical scientists”, with the latter group including mathematicians as well as physicists and astronomers1. Because of the relatively small size of NAS membership, we sent our survey to all 517 NAS members in those core disciplines. Leuba obtained a return rate of about 70% in 1914 and more than 75% in 1933 whereas our returns stood at about 60% for the 1996 survey and slightly over 50% from NAS members1,2.
As we compiled our findings, the NAS issued a booklet encouraging the teaching of evolution in public schools, an ongoing source of friction between the scientific community and some conservative Christians in the United States. The booklet assures readers, “Whether God exists or not is a question about which science is neutral”5. NAS president Bruce Alberts said: “There are many very outstanding members of this academy who are very religious people, people who believe in evolution, many of them biologists.” Our survey suggests otherwise.