Spiritual women are more promiscuous than are non-spiritual women. The study differentiated between “spiritual” and “religious” and though the article focuses on spirituality, the pecking order seems to be spiritual over non-spiritual, irreligious over religious. Their theory:
“Believing one is intimately tied to other human beings and that interconnectedness and harmony are indispensible may lead one to believe sexual intimacy possesses a divine or transcendent quality in itself,” Burris writes. “In fact, ascribing sacred qualities to sex has been positively associated with positive affective reactions to sex, frequency of sex, and number of sexual partners among university students.”
I have an alternative theory.
Being an atheist is undemanding but also unpopular and for a lot of people unfulfilling. Being a member of an organized religious provides you with a packaged set of beliefs but comes with a bunch of rules you have to follow. Call yourself “spiritual” and not “religious” and you can do whatever the heck you want with less in the way of social consequences and you can find meaning in whatever the heck you want to find meaning in. So if it feels good you can make it not about feeling good but about connectedness and all that jazz. The rules are typically more generous when you make them up as you go along. You get gratification from all ends.
That these people would correlate highly with people that engage in promiscuous, unprotected sex is hardly a surprise.