The last 30 years have seen a dramatic shift in British attitudes towards a range of moral issues, including gay relationships, abortion and adult online content.

New research by the Policy Institute at King's College London compared data from 1989 with IPSOS Mori polls of 1,000 British adults conducted this year. 

In just three decades, there has been a significant drop in the number of people who believe gay relationships are morally wrong, down from 40% of the population in 1989 to just 13% today. 

While just over half of people (52%) in 1989 believed that "homosexuals should be treated just like other people", today this figure has jumped to 82%. Significantly, 30 years ago, only 23% strongly agreed with this statement, compared with 64% now.

While a quarter of people (24%) 30 years ago believed that having a child out of wedlock was immoral, this has fallen to only 13% today, with the biggest decline among people aged 55 and above, where levels of moral disapproval have more than halved from 40% to 18%.

Society is becoming increasingly permissive of sex in popular culture, with those believing soft p**n magazines in shops to be immoral falling from 38% of the population in 1989 to 22% today. Women in particular have become much more tolerant of this, down from 46% who believed it was immoral 30 years ago to a quarter today. 

People are also less likely to frown upon full frontal male nudity on the TV, with those believing this to be immoral falling from 39% to 23%.  The biggest change in attitudes to this can be seen in the 55+ age group, falling from 60% to 29%. 

Attitudes towards drug use have also noticeably shifted. The number of people who regard taking soft drugs like cannabis as morally wrong has more than halved in the last 30 years from 60% to 29%. Even taking heroin is less likely to be viewed as immoral by today's adults, down from 89% to 67%.

There has been little change in attitudes towards infidelity, with 52% viewing it as immoral 30 years ago, similar to 55% today.  

Men, though, have become slightly less accepting of unfaithfulness, rising from 49% 30 years ago to 55% today - in line with 54% of women who frown upon it now. 

When it comes to abortion, over a third of people in 1989 (35%) thought this was immoral, but today this has fallen to only 18%. 

There are signs, too, that society is becoming more open to euthanasia, with the proportion of adults who believe this to be immoral falling from 22% to 17%. 

The only issue in the survey that saw a significant increase in moral disapproval was capital punishment, which rose from 22% to 37% of the public since 1989.

The institute said that some of the changes in attitudes could be explained by the ageing Baby Boomer generation replacing the so-called Silent Generation, those born before World War II when social expectations were much more conservative. 

Professor Bobby Duffy, Director of the Policy Institute at King's College London, said: "These findings show Britain has become decisively more liberal on a range of moral issues in the last 30 years.

"That we've gone from being a country in which four in ten thought gay relationships were not just wrong but immoral, and in which only half thought gay people should be treated just like anyone else, to the society we see today, all in the space of a few decades, shows just how much attitudes can change.

"On all sorts of issues, from full frontal male nudity and violence on TV, to drug use and abortion, we are much more relaxed as a nation.

"One of the causes of this shift is that Baby Boomers – who grew up in more permissive times – have moved into older age, replacing a generation born before World War II, who had more conservative views.

"The result is that what were once pressing moral concerns have become simple facts of life for much of the public.

"However, some moral concerns, such as having affairs, have endured across the decades, or have even increased, such as capital punishment."