In the spirit of Valentine’s Day, the Herald Laurie Santos over email about the freaky sexcapades of our primate cousins and the next frontier of hook-up culture. Santos is a professor of psychology and cognitive science here at Yale. She is also head of the Comparative Cognition Laboratory, which studies the evolution of the human mind through examining the mental capabilities of primates. To the non-psych inclined among us, Santos is perhaps best known for teaching “Sex, Evolution, & Human Nature,” otherwise known as “Sexy Psych.”
YH: Since this is a Valentine’s Day themed issue, first things first: are you a fan of the holiday?
Santos: Hmm. This is a tricky one. On the one hand, I’m a big fan of holidays in general. So I’m always game for an excuse to celebrate. That said, I think St. Valentine’s not really the best namesake for a holiday about love and sex. Don’t get me wrong, I’m sure St. Valentine probably did lots of great things, but he’s just some random Italian priest. I think there are lots of way better namesakes for a holiday about love and sex. Personally, I would choose to make everyone celebrate love on (Charles) Darwin Day. He wrote about sex way more than Valentine did, and his ideas about sex have shaped entire new scientific disciplines. He even figured out why love was so important from a biological perspective. That’s why I usually celebrate on Darwin Day (Feb. 12) instead Valentine’s Day. Plus it’s way easier to get a table at a nice restaurant on Darwin Day than Valentine’s Day.
YH: In many ways, the holiday is a celebration of monogamy. What are the evolutionary origins of monogamy?
Santos: Usually, monogamy evolves when two parents are needed to raise an offspring. In most species, it’s often in a male’s best interest to seek out lots of mates rather than deal with the effort parenting. But males don’t have the luxury of doing that if their kids won’t survive without some help. This is why you tend to see monogamy more often in species that have really fragile offspring. It’s why most birds are monogamous (think penguins and their really fragile eggs). And it’s probably one of the reasons that humans across most societies mate as part of a pairbond, since our babies tend to need more care and support than your average primate baby.
YH: Is there a scientific difference between lust and love?
Santos: In general, scientists are big on breaking things up into tinier and tinier constructs so they can study them. So yes, lots of psychologists have tried to find ways to distinguish between these constructs. These days, most relationship researchers think there is a big distinction between lust and love, or what scientists have called “passionate love” and “companionate love,” respectively. These two constructs tend to be linked to different kinds of sensations (with passionate love being more related to novelty and arousal, and companionate love being more related to things like intimacy and caring). But biologically speaking, we still know relatively little about how these phenomena work, and how to manipulate them.
YH: Are our primate cousins as irrational when it comes to love and sex as we are?
Santos: Our primate cousins have lots of their own things to worry about when it comes to sex. I think that’s really one of the big messages when we look at other primates or any other taxonomic group— every sexual reproducer faces their own species-specific worries about love and sex. In primates, you see lots of diversity. Some primates, like tamarins, marmosets, and gibbons, have to worry about findings a good long-term partner to help raise kids, just like humans. Others, like macaques and chimpanzees, have to worry about sneaking around to steal a bit of sex on the side without all the important high-ranking individuals finding out. Still others, like female bonobos, need to use all manner of kinky sexual maneuvers to get into the right clique, or even just to make new friends. So other primates also need to have to put their other rational concerns on hold to navigate their own species-specific sexual landscape, in much the same way as humans do.
YH: Does hook-up culture have evolutionary origins? How is it mirrored in the animal world?
Santos: The question of where hook-up culture came from is still a big open one. One of the things we always say in my PSYC 171 course is that’s it’s often very hard to understand exactly how the human mating system works, because it’s not really ethical to run studies in the way we can with, say, fruit flies. This means it’s often easier to figure out what other animals are doing when they use different mating strategies than it is to figure out what humans are doing. That said, the act of having casual one-time sexual encounters is one that’s pretty popular throughout the animal kingdom. Lots and lots of animals engage in one-night stands: where a male and female meet only once, have sex, and that’s it. Relatively few species do some animal version of texting the next morning to ask for a second date. So even though we make a big deal of this whole “new hook-up culture,” it’s a strategy that lots of sexually reproducing species have used for billions of years.
YH: Humans’ sex and dating lives have gotten a lot more complicated/diversified/freaky since the invention of dating and hook-up sites and apps. Do you think the invention of these technological tools caused these sexual desires to evolve?
Santos: Well, first—since I can’t help but give a shout out to amazing things you see in the animal kingdom, it’s worth noting that even the craziest of behaviors we see in today’s human hook-up culture look pretty prudish compared to the complicated/diverse/freaky things you see in other animals. Swiping for a one- night stand on Tinder looks downright puritan when you compare it to the crazy kinky stuff that other species do. I mean, we’re talking not just one-night stands and cheating, but sequential sex changing, group sex, violent sadism, foot fetishes, water sports, cross-dressing, voyeurism, penis-biting, feces-eating, cosplay, necrophilia… Seriously, name the weirdest kink you can think of, and you’re going to see it in somewhere in the animal kingdom. But that said—yes, it is true that these new apps are letting the human mating system play out in ways that were hard to pull off back in our hunter-gatherer days. But my guess is that all these crazy new tools will just play into the psychological mechanisms we already have, ones that have been set up after millions of years of evolution. Tinder and the like are only going to affect our biology if they stick around long enough to exert a real selection pressure on our minds. And exerting an actual change on how our minds operate can take a very, very, very long time. But it is fun to speculate what human mating strategies will look like in, say, 100,000 years.
YH: What’s the weirdest mating ritual you’ve ever observed?
Santos: One strange thing about my job is that I have to watch a ridiculous number of dirty animal videos when prepping for my PSYC 171 course. So if you mean “observed” as in “observed on video,” believe me—I have seen it all. In terms of live animal sex shows, I have a somewhat less diverse sample. I got to see lions and elephants mating in Tanzania, which was pretty impressive. And if I had a nickel for every time I’ve had to watch monkeys doing it, I could probably fund the two new Yale colleges. But the best animal mating ritual I’ve seen—and maybe the most beautiful mating ritual in the entire animal kingdom—is the courtship dance of the Waved Albatross, which I was lucky to see on a recent trip to the Galapagos Islands. Albatross mate for life, and so they really have to worry that they’re picking the best partner. Potential partners spend hours and hours grooming one another with their sharp beaks, and then they duet by fencing with their beaks and bobbing their heads back and forth. It looks really goofy, but it also seems so loving. And when they look into each other’s eyes at the end… I mean, wow. It’s better than poetry. I cried the first time I saw it. It’s definitely the most romantic thing I’ve ever seen.
YH: Speaking of romantic gestures…what’s the best date place in New Haven?
Santos: These days I’m a huge fan of August in East Rock. It’s cozy and romantic and has amazing wines. But Koffee? On Audubon is also great for a low-key romantic hangout. My husband and I like to take “work dates” there.
YH: Best slice to share?
Santos: I think Modern is the best New Haven Pizza. Particularly when eaten take-out at home with my hubby and a nice bottle of wine.
—Interview condensed by the Herald