Maybe we could take a moment and talk about atrazine and its effect on male sexual behavior in amphibia to the sperm studies because Tyrone Hayes is a wonderful researcher who established a link through his research between atrazine exposure and male sexual behavior of amphibia. Could you elaborate on that?

Tyrone first caught frogs in the wild, in environments that were more or less exposed to atrazine, and showed effects on development and sexual behavior. Then in his lab, he actually exposed them. So he knew exactly who was exposed and how much. And he showed that, and I can't tell you what percent or what, you know, but a significant number of frogs exposed to this pesticide atrazine chose to mate with other male frogs.

Tried to mate with other male frogs, presumably unsuccessfully. Well, they mounted them. He has photos of the males mounting males. That's a remarkable result. It's been kind of, you know, used and misused out there in the media and in popular culture. But if nothing else, it suggests that the organization of the neural circuits and neuroendocrine pathways that control sexual, I don't want to say partner, because it's mating, frogs aren't monogamous, but sexual preference are significantly impacted by this atrazine.

Yes. And it suggests that there are other environmental chemicals as well. And I don't know if we'll have time to go there, but I did work on neurodevelopmental outcomes in relation to prenatal phallic exposure. And so I think the overarching idea here is that the brain, like the genitals, is sexually dimorphic.

And there's many people, by the way, who will take offense at that. Really? Yeah. I think there's, I mean, going back to the work of Frank Beach in the psychology department at UC Berkeley, showed this in beagles. It's been shown in pretty much every species. But it's not a better or worse.

I think this is what people need to hear, like dimorphic does not mean better or worse. It means different. Right. Right. And that there are, for example, advantages to spatial reasoning in a male, which are related to testosterone, right? You know that. I mean, I think there, yeah, I mean, my understanding of this literature, and I'm not an expert in this particular aspect, which is the behavioral phenotypes, but, you know, like the medial preoptic area of the hypothalamus is known to be sexually dimorphic, dependent on testosterone, converted into estrogen during development, et cetera, et cetera.

And there's just so much evidence of this. How it links to behaviors, I think, can be reasonably placed into ethologically relevant, evolutionarily logical arguments when talking about rodents or beagles or even rhesus macaque monkeys. I think where people get a bit inflamed is when people try and take the sexual dimorphisms that have been observed in animal brains, or even in human brains, and tack those to specific abilities or lesser abilities.

I think that's when people sort of go, wait a second, like, I have much better sense of direction than my husband. And you go, well, yeah, like, you know, and then you go, well, does that mean that she has higher testosterone than him? And then maybe, and then, and pretty soon you're in almost a no man's land, a no person's land of confounding variables, right?

And I really appreciate that you raised this. And also that you said it and I didn't, because I feel safer that way. But look, there is a very simple, outdated questionnaire, and it's play behavior. It's called the PSAI. It's been used for years. Have you heard of it? It's a rough and tumble play.

Yes. Yeah. Yes. And there are 24 questions on there, and they are sexually dimorphic, I guess you could say that, you know, my child likes to play with dolls, my child likes to play dress up, my child likes to play rough and tumble, et cetera. And we gave that questionnaire to our population and looked at the answers that the mothers gave, both in our population, by the way, and a Swedish population of a colleague there, Carl Bornahag and Gustav Bornahag.

And what we found, higher phthalate levels, these anti-androgenic phthalates were associated with less masculine male typical play in our male boys. So- This is phthalate exposure to the mom, baby is born in the young human child. Yeah. I think it was four years of age. Four years of age.

Less rough and tumble type play among the boys whose mothers were exposed to more phthalates during a critical period of development. Now you can see that's a politically loaded issue now. I mean, you know, well, I think we're, I mean, let's have some fun with this in the scientific sense.

The notion of dimorphism is, you know, okay, male and female brains are different, right? And male, female defined in those, almost all those studies as presence of a Y chromosome. And then people say, well, there's some, there's XYY, and then there's XXY, okay. But most of the time you're talking about XX chromosome or XY chromosomes at birth.

Forget everything else for the moment. These are always distributions. This is what I think people need to know. We're not talking about, these are not, this is not, you know, two hills of data separated by a valley. These are overlapping distributions, right? So you get males with a "female-like" distribution, you get females with a "male-like" distribution.

And I think as long as we acknowledge that, then we're just talking statistics. We're not placing any cultural or any value on it really whatsoever. But if you could make the analog to the intergenital distance, it's kind of similar. You know, you have the same exposure, phthalate exposure, you have something changed statistically.

We don't see huge differences in the boys' genitals. And we don't see huge, I don't, we know, these kids have not been scanned, so we don't know how their brains look. But based on their answers, we don't see huge differences. We see tendencies. We see they are more likely, if they had been exposed to these phthalates, to want to play dress up and have tea parties.

More likely. Doesn't mean that they're all going to, but that's the direction and so on. So I think we have to just think about more likely, not absolute.