Nearly forty percent of Americans believe that premarital sex is not morally acceptable, while more than four in ten believe the same about having a child outside marriage, according to a new poll by Gallup.
The survey also revealed that more than forty percent believe that sexual relations between people of the same sex are not morally acceptable.
The poll asked a random sample of 1,024 adults about the moral acceptability about 18 types of conduct, including gambling, animal experimentation and cloning.
It found that, while a majority of Americans, 54pc believed that having children outside marriage was morally acceptable, a sizable minority, 42pc believed that it was not morally acceptable.
Similarly, while 59pc of Americans believe pre-marital sex is morally acceptable, 38pc do not agree.
Fifty four percent of Americans believe homosexual relationships are morally acceptable, while 42pc disagree.
The survey also found that 89pc of people believe that married people having an affair is not morally acceptable.
Sixty four percent of people said they believed pornography was not morally acceptable, while 31pc said that it was.
The vast majority of people, 86pc, said that polygamy, where more than two people are involved in a marriage, was not morally acceptable; 11pc said that it was.
On bioethical issues, 51pc said that abortion is not morally acceptable, with 38pc disagreeing, while 86pc said it was not morally permissable to clone human beings.
Fifty eight percent of people said that using human embryos for medical research was morally acceptable; 33pc disagreed.
The poll also showed that 89pc of people agreed that birth control was morally acceptable, but the question did not distinguish between natural birth control, which the Catholic Church favours, and artificial contraception.
Eighty two percent of Catholics said that birth control was morally acceptable, compared to 15pc who said it wasn't. Ninety percent of non-Catholics agreed that birth control was morally acceptable, with six percent disagreeing.
Overall, the survey found that there had not been much movement in American attitudes on these issues, apart from attitudes to the death penalty. The survey found that 58pc of people thought that the death penalty was morally acceptable, down from 65pc in 2011 and the lowest level of support since Gallup started asking the question in that format.