Darrel Ray, raised a fundamentalist Christian in Topeka, Kan., shed a heavy cloak of guilt surrounding sex after he left the church in the late 1970s, and wondered if his experience reflected that of others.
Today, he has finished research that he said bore out his hypotheses -- that religion and good sex don't mix. In an online survey of 14,500 people who had come from a religious background, he discovered that once they had abandoned their churches, their sex lives improved.
In his survey, "Sex and Secularism," which he publicized last week, Ray drew a direct correlation between guilt and sexual behavior. Not surprising, but he also learned that guilt eventually subsides.
"We find guilt is a pretty big thing," said Ray, the author of, "The God Virus: How God Infects Our Lives and Culture."
Atheists, he concluded, had the best sex of all. "They can speak with some authority," he said. "They were raised in very secular homes."
All his respondents -- over 18 and all sexual orientations -- had abandoned their churches and described themselves as agnostic or without a religious belief.
Once they left religion, more than 50 percent saw improvements in their sex lives, 29.6 percent saw no change and 2.2 percent said it was worse, according to his survey.
Those who had grown up in the most conservative churches -- based on their teachings on sex and invocation of guilt -- reported the highest satisfaction levels after leaving religion behind.
All of the people who were questioned were found to have sex around the same number of times a week. They also became sexually active at similar ages.
Those who had been raised Mormon with their strict views about sex, showed the highest rating among those who had sexual guilt with an average score of 8.19 out of 10. Others with similar responses were Jehovah's Witness, Pentecostal, Seventh Day Adventist and Baptist.
Catholics, on the other hand, rated their guilt at 6.34 and Lutherans came in at 5.88. Atheists and agnostics were the lowest in guilt at 4.71 and 4.81.
People who had abandoned their beliefs said their sex lives were "much improved" and rated their new experiences on average as 7.81 out of 10.
Ray, 60, is an independent researcher who has worked as an organizational psychologist in corporations for 30 years. Before that, he spent a decade as a clinical psychologist.
"For decades I have heard that people felt their sex life was better once they left religion --- any religion -- but no one seemed to have examined this scientifically," he said.
He and his assistant, Kansas University psychology student Amanda Brown, conducted an online survey that drew 2,500 responses an hour. He only surveyed those who had said they were once religious, not those who today practiced their faith.
Rays' respondents were predominantly highly educated and affluent. They included hetero, same-sex and intersex couples. In the first day, he received 2,500 online responses.
"I was blown away," he said. "People wanted to tell us their life story. This is not just about sex, it's about emotions."
"His results make a lot of sense -- why people who are religious emphasize guilt in sexual behaviors," said Tara Collins, president of a multidisciplinary group of researchers at Kansas University's psychology department, who gave Ray feedback after he presented his survey results.
Collins and others were impressed, but they did express concern about his causal statements and urged him to make some modifications. Ray, she noted, had not looked at the satisfaction level of those who continued to practice their faith.
His research will not be published by an academic institution because it has not been peer-reviewed.
But, Mark Regnerus, an associate professor of sociology at the University of Texas at Austin, and the author of two books on the subject of sexual behavior in adolescence and young adulthood, said Ray used unscientific methods.
"It appears that it was a 'fill it out if you want to' kind of survey that is not random, not nationally representative, and relies entirely on self-selection," he said. "In other words, they have data from people who felt like filling out a survey on atheism and sex. As a result, I am not surprised at their findings."
Regnerus, in his book, "Forbidden Fruit," said he had found a connection between religiosity and anticipated guilt among teens who had never had sex.
"Otherwise, most of what we know about this is hearsay or guesswork," he said.
He also said Ray was not an "established" researcher at a university, where most studies of this kind are carried out. "I don't fault the author for running the survey he did, but it does display research methods which do not meet the standards of most published social science."
Ray admits the study was self-selective. "I can't even imagine any research that is not self-selecting," he said. "Kinsey was self-selecting. They may make stabs and efforts at randomness, but it's hard to get that with sex."
He said that in addition to sexual satisfaction, he survey concluded that religiously conservative parents were perceived to be less effective at sex education.
One of the biggest surprises in Ray's research was that people are not "plagued with guilt" long after they leave their earlier religious beliefs.
"We just couldn't find evidence for that," he said. "Not to say that some people aren't, but statistically, people get on with their sex lives and have a lot of fun. They don't wish Jesus back in the bedroom. And it doesn't matter if they are Mormon or Muslim or Pentecostal when God is watching."