[0:02]What are the data on how females signal um let's just say, you know, testosterone, estrogen and um other, you know, uh relevant hormones and for males as well. What are the what are the external signals? Or behavioral or behavioral signals. Yeah, so there's so they that that's a really important point that you made because the both, you know, those things go together. So, uh, it's been most controversial for females, but you know, in my view, the data is pretty clear and it, you know, aligns I think with our own intuitions um just from from daily life, which is well some things are are apparently not consciously perceptible. It's like hard to report, but um, but through studies where you just ask males for like, okay, is this, you know, how attractive is this woman or etcetera, um, that there are changes in the face, for example, and that's been one argument is that this is going to sound funny, but that the signals that in non-human primates are in the rear are because we're walking upright, you can't see that really. So now it's kind of in in the face and so these changes that um happen that the ovulatory cycle is reflected in the turgidity, how how tight the skin is in the face because it gets a little plumper and a little bit redder. And we may not be consciously aware of that, but that that that it's there, right? And it shows up in sort of preference data when when you when you ask heterosexual males, you know, do you, you know, how attractive is this woman, etcetera? So that that seems to be the case. Um, and also um behavioral, you know, so, so uh sort of flirtatious behavior, um, increases around the time of ovulation. Yeah, yeah, yeah. Uh, there's there is a classic study that um that exotic dancers, strippers, um, would actually get bigger tips, more tips when they were ovulating than when they're not ovulating. Interesting. So there may be, you know, And it could be by it could be by virtue of their their behavior. It could be the way they they dance proximity to the uh to the whatever I guess the observers, clients, whatever you call them. I I don't recall that being um quantified, but um, but it suggests that there's there's a latent signal there. And that uh men are uh unconsciously processing this. They're not saying, oh, her cheeks are particularly uh plump and red right now there that um, but that if you measure their ratings or their scores of attractiveness, when she's ovulating, it's these features that are that might be drawing out that response. Correct. We can take this back to the monkey porn studies, which is was our first real foray into trying to quantify the uh the value of various kinds of social information for guiding decisions. And we already came into this uh with a sense that like, yeah, things like status, physical prowess, mating status, um, you know, are you are you um, you look like a good mate, bad mate, are you in in mating condition, you know, etcetera? And so when you know, you think about that like, how do you ask a monkey that question? You could ask him, they're not going to tell you because they they can't talk. But you have to develop a behavioral way to elicit that. And so we did, I think it was pretty clever, was to riff on the studies that, you know, I had already done looking at varying the expected value of two options. So this was the work I did as a postdoc with Paul Glimcher, where we um revealed uh economic signals in the brain and the in the parietal cortex in an area between where visual signals come in and where you make a choice um to to make a behavioral response.
[4:30]And we varied like in this case, monkeys don't work for money. They'll work for juice, okay? It's been actually it's really fun. You spend a lot of time figuring out what juice they really love best. And to then economically you would vary like the the size of the juice reward that each of the two offered or its probability while maintaining size constant, that when you combine those, you multiply those together, you get expected value. That's the first model of economic decision making that was really ever developed, right? You compute the expected value of different options, you choose the one that has the highest value. It it, you know, doesn't work all the time, but it's sort of a rough proxy and we showed that yeah, neurons in cortex signal that. Monkeys are good economists, they choose the one that has a higher expected value. Okay, so now take that experiment. I'm going to have monkeys choosing between two options that vary in how much juice they pay out. But I'm also going to pop up a picture when they choose one of them. Okay? And they don't know what picture is coming up, but the picture is going to be it could be a it could be a nothing burger, just like some gray square, it doesn't mean anything. Or it could be the the perineum or of a female if it were males that we were studying, we did this with males, uh sorry females making choices eventually as well. Could be the face of a dominant male, the face of a subordinate male, the face of a female, etcetera. What's the equivalent of of the uh swollen taint of a female monkey um for if you reverse the experiment and it's the female monkey who's making a choice about male monkeys, what are they what do they find really attractive in a male monkey? Yeah, so it's the taint of the male monkey because it's providing a signal of how much So it's just monkeys looking at taints of other monkeys.
[6:36]How much testosterone is circu, you know, that they've got on board basically, which is a good predictor of their status. Um, it's a good predictor of their, you know, fighting ability, all that kind of stuff. And if you're a female and you you that that that's a reasonable kind of choice to make because if you have male offspring and females are predisposed to choose that then they'll your male offspring are going to do pretty well. So that's what we did. And we varied how much juice. So sometimes monkeys would get paid. They'd have to give up juice to see the pictures. Sometimes they'd get paid more to see the pictures. And what we did then is we we we constructed a choice curve and we use the differential, if that if it's not 50/50, if it slides one way or the other, it tells us that monkeys are are paying X amount to to see certain kinds of pictures or you have to overpay them, right? And so what did we find? It was really I think scientifically revealing, but it's pretty fun. People got it immediately. Uh they will pay juice. Juice. They will give up juice. They will pay it to see pictures of the perineum, the hind quarters of females. Um by uh dominant male faces um and that correspondence I thought was pretty compelling.
