This week, YouGov released a poll questioning British people about their sexuality. The poll made headlines because nearly half of all 18-24 year olds said they were not fully heterosexual.

More specifically, the poll asked people to rank themselves on the so-called Kinsey scale, a measurement named after fraudulent researcher Alfred Kinsey. The Kinsey scale ranges from 0 (fully heterosexual) to 6 (fully homosexual). All the other numbers represent a range of sexual attractions – 3, for example, would be fully bisexual, i.e. equally attracted to both sexes; 2 would be more attracted to members of the opposite sex than the same sex, but still attracted to the same sex.

The poll showed that 88 percent of those older than 60 in the United Kingdom identified as completely heterosexual. In each succeeding age bracket, that number dropped: 78 percent for those aged 40-59, 58 percent for those aged 25-39, and just 46 percent for those aged 18-24. The number identifying as completely homosexual skyrocketed for younger generations as well: for those aged 60 or above, just 1 percent identified as homosexual, 3 percent of those aged 40-59, 9 percent of those aged 25-39, and 6 percent for those aged 18-24.

This poll goes to the heart of the question of whether sexual orientation is purely biological, or whether it is societally impacted. Sexual orientation, according to the American Psychological Association, “refers to the sex of those to whom one is sexually and romantically attracted.” The massive change over a short period of time in sexual orientation in Britain can only be explained in one of two ways: biology or biology combined with environment.

Biology. The argument that sexual orientation is solely a biological phenomenon is extraordinarily weak, and this poll proves it. Evolution does not favor high prevalence of homosexual attraction. Homosexuality prevents reproduction, the chief goal of natural selection; while some scientists make the case that homosexuality has been preserved evolutionarily in order to preserve altruism for purposes of “kin selection,” a high prevalence of homosexual attraction would threaten population growth. Furthermore, since homosexual activity is highly linked in the human population to higher rates of disease and lower life expectancy, the notion that evolution would favor higher rates of homosexuality would be a difficult one to support. And even if one could make that argument, the skyrocketing rate of non-heterosexual sexual orientation would not multiply from 12 percent to 54 percent in two generations through pure natural selection.

Unless, of course, generation upon generation of British people have been lying about their sexual orientation. To argue that, one would have to argue that society forced four in ten British people submerged their non-heterosexual tendencies in order to live heterosexual lifestyles – that the natural percentage of the population that feels non-heterosexual is over half. That’s a stretch. The “all previous generations led a lying lifestyle” argument also implicitly acknowledges that sexual behavior is highly mutable, even if you believe sexual orientation is not.

And even if society did forward heterosexuality at the expense of non-heterosexual feelings, that begs the question as to whether society is happier now than it was generations ago in terms of sexuality – does society’s current attitude liberate people from the shackles of binary sexuality, or does it encourage those who could engage in healthy heterosexual relationships to choose alternatives that are statistically more physically and psychologically damaging?

Environment. Then there is the second possibility: that sexual orientation is not purely biological, that social environment impacts sexual orientation, not just sexual behavior to an extraordinary degree. The rate of non-heterosexual identification in Great Britain has skyrocketed 450 percent in two generations, according to this poll. As society grows not only more accepting of homosexuality, but outwardly celebratory of it; as children are taught that morality has nothing to say about choice of sexual partner; as people are punished for suggesting that society value heterosexuality above homosexuality; as bisexuality becomes the “tolerant” and “cool” sexual orientation (and if you ask young people, it is), more and more young people plumb the depths of their hormones in search of bisexual tendencies. Where once, people embraced the societally-approved standard of sexual orientation, reinforcing heterosexual feelings while rejecting homosexual ones, now they embrace all sexual attractions of every kind, enshrining them rather than treating them as aberrant exceptions to a general rule. If a 12-year-old girl liked boys at school but had a lesbian dream in 1950, her parents probably told her that puberty led to confusion, but that heterosexual orientation would clarify over time; today, we would treat her as a burgeoning LGBT heroine, and bar her parents by law from telling her otherwise.

Perhaps, as a society, we worry less about the increased sexual confusion among young people than about the impact of a heterosexual norm on those who are immutably non-heterosexually oriented. That seems backward on a societal level, both in terms of pure number of people affected and in terms of the value of heterosexuality to society generally, but at least the argument has draw to it.

But that’s not the question here. The question is whether sexual orientation is biological and immutable, as LGBT advocates routinely insist, or whether sexual orientation can be impacted by environment, which would raise serious questions about the nature of educating children on sexuality. This study, now being championed as a great victory by the LGBT community, strongly suggests the latter is true: how we treat homosexuality as a society has massive influence on the sexual orientation of individuals within that society, for good or ill.

Ben Shapiro is Senior Editor-At-Large of Breitbart News and author of the book, The People vs. Barack Obama: The Criminal Case Against The Obama Administration (Threshold Editions, June 10, 2014). Follow Ben Shapiro on Twitter @benshapiro.