The GSS provides empirical evidence lending support to that claim. In 2008, the survey aksed respondents to self-describe as religious and spiritual, religious but not spiritual, spiritual but not religious, or neither religious nor spiritual. Being spiritual but not religious is a SWPL staple--it allows for a connection with some higher power without adherence to any of the three major monotheistic faiths (think white liberal Buddhists or Wiccans). The following table shows the ratio of the religious but not spiritual to the spiritual but not religious. Because the question has only been posed once, sample sizes for Hispanics and Asians are too small for use:
Religiosity is the virile manifestation of supernatural belief. Spirituality is its more effeminate version.
GSS variables used: RELSPRT, SEX, RACECEN1, POLVIEWS
* As the acronym SWPL phonetically rolls off the tongue as "swipul" and others in the Steveosphere have apparently adopted it, I've elected to retire "whiterpeople" as the noun of choice for the people satirized by Christian Lander.