How & Why Did Humans Start Having Oral Sex? The Answer, According To Science Is Weird AF

There's no denying that oral sex feels great - but when you think about it, it's pretty weird. How did humans discover that giving head was so satisfying? It turns out that some evolutionary reasons explain our love for oral sex. Here's the science behind oral sex - these strange reasons may surprise you.

Ingesting your partner's semen is healthy for you.

Although it may seem strange, swallowing your partner's ejaculate can actually have some strange health benefits, particularly if you are planning on having kids with them. That's because semen contains DNA, so it makes your immune system more tolerant to your partner's DNA. That way, when you have kids, your pregnancy will be easier on your body, because your system is already familiar with them. Swallowing semen during your pregnancy can even reduce morning sickness! Crazy, but for anyone that's ever been pregnant, you know that's a pretty good motivator to try oral sex.

Oral sex may prevent you or your partner from cheating.

Oral sex is a very intimate experience, and many scientists believe that partners through the years have used it to stay focused on their partners instead of cheating. While there isn't really hard proof of this, the logic behind it makes sense - women often orgasm very easily from oral sex, so when they're having it frequently, they're going to feel more satisfied. Giving oral sex also helps you stay very focused on your partner, because to satisfy them, you need to be very attuned to their needs and preferences. The intimacy and satisfaction are also intended to help you focus entirely on your partner, instead of straying to someone else.

Oral sex prolongs the experience for both partners.

Oral sex isn't always used as foreplay, but from a scientific perspective, it makes sense that it would be used for this purpose. Since women take longer to become aroused, oral sex can help get them on the same level as their partners very effectively. It's also been theorized that men who receive blow jobs before having sex will last longer during intercourse due to the increased lubrication.

Early humans used it to detect unfaithfulness.

During the time of cavemen, there weren't too many easy ways to determine if your partner was cheating on you. Because of this, cavemen would go down on their female partners to try to sniff out if they'd been with someone else. While the effectiveness is obviously debatable, it does explain some of the motivation behind why humans started having oral sex.


Turns out, humans have been enjoying oral sex for thousands of years. These evolutionary reasons for trying it out may be a bit strange, but they've led to a practice that is incredibly intimate and satisfying. As if you needed another reason to ask your partner to go down on you! But in the long run, you don't need to take the science behind it too seriously. One of the biggest reasons for enjoying oral sex is purely because it's fun and enjoyable.