We are in the midst of a sex recession. Young people today are having half as much sex as previous generations did, roughly the same amount as seniors.Solutions to this decline tend to place the burden on women. Go online and you’ll find endless advice urging women to get their sex drive back. Self-help books, herbal supplements and pharmaceutical ads promise to reignite female libido, as if women’s desire is something that mysteriously breaks and needs to be repaired.For decades, women’s lower sexual desire has been treated as biological fact — the product of evolution or hormonal destiny.But the experiences that shape desire tell a different story: The libido gap begins long before adulthood, in the earliest experiences that teach young women what sex is like and who is entitled to enjoy it.Early experiences of sexAdolescence is a window of opportunity for learning how to have healthy, enjoyable sex. The adolescent brain is especially attuned to reward and peer social connection, so early experiences with closeness, communication and pleasure can leave lasting marks.And yet it is during this window — when interest in sex comes online and the brain is primed to learn from experience — that most young women get the worst sex of their lives.Across studies in North America and Europe, adolescent girls’ first sexual encounters, especially with boys, are more painful, less pleasurable and more ambivalent than boys’ first experiences. Fewer than one in 10 young women report orgasm during their first sexual experiences. The “orgasm gap” at this milestone is rarely discussed and is roughly three times larger than the one that later makes headlines among adults.These differences reflect the unequal conditions under which sexual learning unfolds. At precisely the developmental moment when experience teaches the body and mind what intimacy feels like, adolescent girls are most likely to learn that sex is something to endure rather than enjoy.That learning accumulates over time.Fixing the wrong problemAdolescence is when desire itself is shaped, as the brain wires connections between pleasure and motivation. Unequal experiences during this period can have lasting effects on sexual comfort, confidence and interest. What begins as differences in experience can come to look like differences in biology.But that can change when early experiences are more equal. When young people approach sex as mutual exploration and feel safe enough to express what feels good, the pleasure gap shrinks — and so does the desire gap. Same-gender encounters, for instance, tend to involve more mutual stimulation and higher satisfaction for women, a reminder that what shapes sexual pleasure is not who one’s partner is, but whether pleasure is treated as mutual.We continue, however, to focus on the symptoms of low desire instead of the the bigger picture. We treat women’s low sexual desire as a problem to be fixed. We prescribe pills, sell devices and urge women to change their mindset. These fixes that promise to help women reclaim their desire are trying to recover something that was never lost and override lessons learned when the brain was most sensitive to experience.Desire is shaped by learning that sex can be safe, reciprocal and pleasurable — lessons not everyone has the privilege to learn.Women’s pleasure has never been evenly valued, and it is especially overlooked when it comes to adolescent girls. From the start, they receive mixed messages about sex: be desirable but not desiring, participate but don’t ask for too much, endure discomfort quietly.These early lessons matter.These unequal experiences also teach boys what sex is supposed to be like. Many young men grow up learning that sex should be consensual but not necessarily mutual, often ending when the man “finishes.” Read more: Want more orgasms? Choose a woman partner Desire was never lostIs it any surprise, then, that half of adult women report ongoing difficulties with sexual desire? Treating this as a personal or medical defect, however, misses the mark. Women don’t lose their desire for sex; they simply learn earlier in their lives whether sex is likely to be enjoyable and equitable. Their bodies and minds adapt wisely letting them know whether their pleasure will be prioritized, treated as secondary or ignored altogether.This doesn’t mean women are doomed to low libido as adults. Desire continues to be shaped by experience throughout adulthood, although learning later in life often requires more conscious effort than the automatic imprinting that happens in adolescence.Recognizing that desire was learned — not broken — can itself be freeing. But helping women adapt as adults sidesteps the real issue: women are taught as girls that their pleasure comes second.And although we can’t change the past, we can still change the conditions under which sexual learning is happening now in relationships, in cultural messaging and in the spaces where young people learn about intimacy. If women want to desire sex and experience it as fulfilling, that is.Emily Impett receives funding from the Social Sciences and Humanities Research Council of Canada.Diana Peragine receives funding from the Canadian Institutes of Health Research.