How We Believe_ Science and the Search for God - Michael Shermer [47]
This assumption is beginning to change. Behavioral geneticist Thomas J. Bouchard Jr. directed the famous “Minnesota twins” study, one of the best known and most extensive studies to date. Bouchard and his colleagues have attempted to cleave the relative influence of nature and nurture on a number of variables long thought to be primarily under the control of the environment, including personality, political attitudes, and even religiosity. Studying fifty-three pairs of identical twins and thirty-one pairs of fraternal twins reared apart, looking at five different measures of religiosity, the researchers found that the correlations between identical twins were typically double those for fraternal twins, “suggesting that genetic factors play a significant role in the expression of this trait.” How significant? While admitting that their findings “indicate that individual differences in religious attitudes, interests and values arise from both genetic and environmental influences … genetic factors account for approximately 50 percent of the observed variance on our measures.” That is to say, about one-half of the differences among people in their religious attitudes, interests, and values is accounted for by their genes. After offering a proviso that much more research needs to be done in this area, and that this single study must be replicated, the twin-study experts concluded: “Social scientists will have to discard the a priori assumption that individual differences in religious and other social attitudes are solely influenced by environmental factors.” Nancy Segal, in her 1999 book on twins, Entwined Lives, points out that genes, of course, do not determine whether one chooses Judaism or Catholicism, rather, “religious interest and commitment to certain practices, such as regular service attendance or singing in a choir, partly reflect genetically based personality traits such as traditionalism and conformance to authority.” Clearly the fact that identical twins reared apart are more similar in their religious interests and commitments than fraternal twins reared together indicates that we cannot ignore heredity in our search to understand why people believe in God.
Taken at face value, a 50 percent heritability of religious tendencies may sound like a lot, but that still leaves the other half accounted for by the environment. Given the range of variables that individuals encounter in their religious experiences, there is much research still to be conducted. Virtually all studies implemented over the past century have found strong environmental factors in religiosity, including everything from family to class to culture. In other words, even with a genetic component to religiosity we still must examine other variables.
IS THERE A GOD MODULE IN THE BRAIN?
During the month of October 1997 the media had a field day when the renowned University of California-San Diego neuroscientist, Dr. Vilayanur Ramachandran, delivered a paper at the annual meeting of the Society for Neuroscience, entitled “The Neural Basis of Religious Experience.” One reporter stood outside Ramachandran’s office and declared, “Inside this building scientists have discovered the God module.” Robert Lee Hotz for the Los Angeles Times reported: “In what researchers called the first serious experiment aimed at the neural basis of religion, scientists at the UC San Diego brain and perception laboratory this week said