If they cheated on an exam, lied to their parents or engaged in serious petting, it's not bearing down on their conscience, according to a study by UNC-Chapel Hill researchers. At least it's not making them feel more guilty than their non-Catholic peers.

The emotional fallout of transgressing the Catholic Church's long list of sins -- venial and mortal -- may be a thing of the past. Blame the decline of ruler-wielding nuns at Catholic schools, or assimilation into the wider society.

The study, to be published this month in the Review of Religious Research, is based on data from the National Study of Youth and Religion conducted by sociologist Christian Smith, now at the University of Notre Dame and Stephen Vaisey, at UNC-CH. The survey included 3,290 teens, of whom 819 were Catholic -- about 24 percent, roughly equivalent to the proportion of Catholics in the U.S. population.

The survey asked teens 13 to 17: "In the last year, how often, if ever, have you found yourself feeling guilty about things in your life?" and "How much, if any, of those feelings of guilt do you think were caused by religious influences?"

Teens who went to confession, now called the sacrament of reconciliation, were no more likely to feel guilty than non-Catholic teens. However, those who did reported higher levels of relief from guilt.

Smith said Catholic teenagers may not know enough about church teachings -- especially about premarital sex, birth control or abortion -- to feel guilty about disobeying. "They haven't internalized it, or they disregard it," said Smith.

Changing values probably also account for a drop in Catholic guilt, said the Rev. Joseph Vetter, Duke University Catholic chaplain. Catholics used to feel guilty for not attending Mass on the Sabbath, or for living together before marriage. For many, those behaviors are now common.

Next up? Smith said he is examining Jewish guilt.