Almost half of young people in the UK would not define themselves as “100% straight”.

YouGov asked 1632 people to plot themselves on a Kinsey scale of sexuality, from 0 (exclusively heterosexual) to 6 (exclusively homosexual).

Among the population as a whole, 72% of adults chose 0 (exclusively heterosexual) – with just 23% differing.

4% ranked themselves as exclusively homosexual, with 19% identifying as somewhere on the spectrum in between the two.

However, among 18-24 year olds – who are likely to have grown up in a more accepting environment – the figures are shockingly different.

Just 46% of young people would rank themselves as 0 (exclusively heterosexual) – compared to 49% who picked something else.

However, the sharp increase is not due to a much greater proportion of people who are exclusively gay -with just 6% identifying as exclusively homosexual.

Rather, 43% of people identify themselves as somewhere between exclusively homosexual and exclusively heterosexual – showing people increasingly see sexuality in a less polarised way.

Generationally, it the biggest difference is from the over-65s – 89% of whom identify as either exclusively homosexual or heterosexual.

Just 7% of over-65s would rank themselves somewhere between the two on a scale – showing how much the concept of fluid sexuality has grown in modern times.

YouGov concludes: “Clearly, these figures are not measures of active bisexuality – overall, 89% of the population describes themselves as heterosexual – but putting yourself at level 1 allows for the possibility of homosexual feelings and experiences.

“More than anything, it indicates an increasingly open minded approach to sexuality. In a further set of questions asking if respondents could conceivably be attracted to, have sex with or have a relationship with someone of the same sex (if the right person came along at the right time), level 1s were at least 35% more likely to say they could than level 0s.”