The weirdest things we learned this week: Animal prostitution and Pavlovian pee responses

Our editors scrounged up some truly bizarre facts.
Cute young baby brown tufted Capuchin monkey looking up and raising his hands like he is begging or praying

What’s the weirdest thing you learned this week? Well, whatever it is, we promise you’ll have an even weirder answer if you listen to PopSci’s hit podcast. The Weirdest Thing I Learned This Week hits iTunes, Anchor, and everywhere else you listen to podcasts every Wednesday morning. It’s your new favorite source for the strangest science-adjacent facts, figures, and Wikipedia spirals the editors of Popular Science can muster. If you like the stories in this post, we guarantee you’ll love the show.

Fact: Monkeys know how to use money (and also how to trade it for sex)

By Rachel Feltman

The first thing you need to know is that monkeys—not apes, our super-close evolutionary cousins, but capuchins like Marcel from Friends—understand money. Several studies have demonstrated that they easily pick up the concept of trading specific tokens for different things they value (read: marshmallows and grapes). They can figure out how to seek out good deals and how to respond to supply and demand, and they’ll try their hands at gambling. According to a 2005 study on the subject, they’ll even learn to sell sexual favors. On this week’s episode, I dive into a few controversial conclusions scientists have come to about prostitution in the animal world. You’ll never look at Marcel quite the same way.

Fact: Redheads need more anesthetic at the dentist

By Claire Maldarelli

As a redhead, I am constantly told strange myths about my hair color. But there’s one I was told recently that triggered my curiosity: “You must have trouble at the dentist.” This acquaintance explained that they’d heard I wouldn’t respond as well to lidocaine as those without red hair. And it turns out there’s research to back this factoid up.

Red hair is one of the rarest hair colors, gracing just two percent of the global population. To gain this auburn hue, a person usually inherits a mutation in the MC1R gene, which is responsible for pigmentation. It typically gives way to the production of a substance called pheomelanin, which results in red hair and fair skin.

But that same gene is also responsible for how the body responds to pain. In a 2004 study, researchers found that redheads, on average, needed about 20 percent more general anesthesia than people with blonde or dark hair coloring. A 2005 study also found that redheads need more lidocaine for dental procedures than their non-redhead counterparts.

Unfortunately, the key mechanism through which the MC1R gene influences pain perception is still not entirely clear. Understanding these mechanisms could help researchers better treat pain in people with red hair, but could also help researchers better understand why everyone experiences pain differently—and how to better manage pain in everyone.

Fact: Your brain can trick you into having to pee

By Jason Lederman

Have you ever been on the way home and noticed an intense need to use the bathroom? Like, you’re putting the key in the door and you suddenly have to pee more than you have in your entire life? Well, it turns out there’s a term for this: latchkey urgency (or if you have a little leak, latchkey urgency incontinence).

I found this topic thanks to Mel Magazine (via Reddit). It turns out the average person should use a restroom 6-8 times a day, which means the bladder takes about 3-4 hours to fill up; by needing to go more often than that, latchkey urgency is technically an overactive bladder condition. It can result from a physical issue like a weak pelvic floor, or a Pavlovian response from just being near your bathroom. But don’t worry, there are ways to train your brain and bladder to reduce latchkey urgency. The UK’s National Health Service has some good tips, as does Shape. And if you think your pelvic floor could use a workout, check out our guide to keeping it in shape.

If you like The Weirdest Thing I Learned This Week, please subscribe, rate, and review us on iTunes (yes, even if you don’t listen to us on iTunes—it really helps other weirdos find the show). You can also join in the weirdness in our Facebook group and bedeck yourself in weirdo merchandise from our Threadless shop.