Do Only Humans and Dolphins Have Sex for Pleasure?

You've probably heard this one before: humans and dolphins are the only species that have sex for pleasure. It's become one of those "fun facts" that gets repeated at parties and shared on social media. There's just one problem—it's completely false.

The reality is far more interesting. Scientists have documented pleasure-based sexual behavior in dozens of species, from bonobos and pigs to lions and Japanese macaques. The myth likely persists because it makes us feel special, but the evidence tells a very different story.

The Science of Animal Pleasure

How do we know animals experience sexual pleasure? Researchers look at several key indicators. First, they study brain structures—the limbic neural mechanisms that generate pleasure and displeasure are remarkably similar across all mammals. Studies on the brain reward system show that what feels good to us likely feels good to many other species too.

Second, animals engage in sexual activities when reproduction is impossible. Female primates have sex during pregnancy. Lions mate far more frequently than necessary for reproduction. Japanese macaques engage in same-sex encounters. If sex was purely about making babies, none of this behavior would make sense.

Perhaps most convincingly, researchers documented female copulatory orgasms in Japanese macaques, observing orgasmic responses in 80 out of 240 individuals studied. Studies on cows and mares found that clitoral stimulation during insemination actually improved reproductive success, suggesting pleasure serves a biological function.

Who Else Is Having Fun?

The list of species that appear to enjoy sex is surprisingly long:

• Bonobos – Our close relatives use sex for social bonding, conflict resolution, and yes, fun
• Pigs – Commonly cited alongside humans and dolphins as pleasure-seekers
• Lions – Both males and females engage in same-sex behavior; their frequent mating suggests enjoyment
• Primates – Virtually all monkey species seek sex even when they can't reproduce
• Marine mammals – Orcas and various dolphin species, not just bottlenose dolphins
• Other mammals – Oral sex has been documented in fruit bats, horses, goats, cheetahs, hyenas, sheep, and cattle

Masturbation—another indicator of pleasure-seeking behavior—has been observed in primates, birds, rodents, livestock, deer, and marine mammals. If animals only cared about reproduction, solo activities wouldn't be on the menu.

Why the Myth Persists

Humans have a long history of underestimating animal emotions and experiences. For centuries, scientists operated under the assumption that animals were essentially biological robots, driven purely by instinct. The idea that other species might experience pleasure, joy, or emotional complexity challenged human exceptionalism.

The "humans and dolphins only" myth is particularly appealing because dolphins are intelligent, charismatic animals. It creates a neat narrative: two smart species, different enough to be interesting, similar enough to be flattering. But science doesn't care about neat narratives.

As researcher Jonathan Balcombe points out, the sheer prevalence of non-reproductive sexual behavior across the animal kingdom suggests that sexual stimulation is pleasurable for many species. Nature didn't reserve good feelings exclusively for humans—or even just for mammals.

So the next time someone tells you this "fact" at a party, you can set the record straight. The animal kingdom is a lot more pleasure-seeking than we once believed, and that's a far more fascinating truth than the myth.