 Hi guys. Today marks the fifth in the series I am doing all this month on explaining lesser talked about parts of autism. And I left yesterday off saying that today I was going to cover fear, the difference in the increased fear response in autism, the digestion problems in autism, and the decreased rate of allergic responses in autism. Things that sound like they have absolutely nothing to do with each other, but actually do. For today we're going to need to be talking about hormones, and four hormones in particular. Ones that don't get talked about all that often, or do but only like one or two of their effects. So assuming, you know, very little about this. Hormones are chemicals in the body that are responsible for signaling kind of like a less fast version of the nervous system. So they'll still relay messages throughout the body triggering certain things, but it's not the ultra quick like oh you see something and immediately process it kind of thing. They're more efficient, less quick, but incredibly important. Nearly every single form of life has some level of hormones going on, even outside of the animal. One of these hormones is histamine, which you almost certainly recognize as having something to do with allergies, and you would be correct, but it has a lot more to do with that. See, nature likes being really, really efficient. And so if it can figure out how to reuse something for multiple purposes, it's going to. Histamine has roles in regulating blood pressure, and that's actually where the allergic response comes from, at least part of it. Histamine has sort of two components there, but by causing your blood vessels to dilate or get bigger, it helps certain chemicals sort of fall out of your blood and get picked up by the lymphatic system or be swept out of the body. So that's sort of why it gets used as part of the immune response and shows up with allergies, but that blood pressure role is useful for other reasons as well. And I'll touch more on that after we cover the four hormones and I start talking about what they have in common. So then the one everybody really knows is the nasal response, that you get a runny nose, tend to be a bit itchy, eyes get a little bit watery, that kind of thing. Now, I'm not going to be citing specific studies, there's a lot for this one, but in there is findings that when well controlled for, allergies are shown to only exist in about 9.4% of people with autism, which sounds high, except that allergies show up in 30 to 40% of the population. You are three times less likely, or a third as likely to have allergies if you're autistic. Now, there are some studies that say the allergic response or more particularly the prevalence of asthma is more common in the autistic. Why I said good controls and this will be a repeated thing throughout this series, figured that out yet, is that, and the studies do say this, which is surprising that they don't realize their own mistake. The samples that they are using, the parents of individuals with autism are more likely to be smokers. And so that throws the whole thing off, because now you're looking at, okay, when you combine autism and parents who smoke, which means likely second hand exposure to smoke, how do the asthma and allergy rates, how are they affected? This is why what good controls are important. You only want to be looking at how does autism affect allergic response. And like I said, seems to be about 9.4 versus 30 to 40. So quite a bit lower. Histamine also has roles in your sleep weight cycle and how alert you are. I wasn't kidding when I said nature likes to be really efficient with reusing things. And then histamine also has roles with the production of gastric acid. Produce more histamine, get more gastric acid or your stomach acid, which is obviously an important thing in being able to digest the food you eat. You don't have enough stomach acid, you're going to have a hard time digesting the foods that gastric acid is used to digest. Next up we have acetylcholine, which is also a regulator of blood pressure. Also alertness, not so much with the sleep weight cycle, but it does have that shared role with how alert you are overall. Similarly with attention, those two have a lot to do with each other, but they are technically different things. Acetylcholine also has a role with your urination and again with gastric acid, but also with saliva. Now, histamine doesn't have too much of an effect with saliva, but acetylcholine does, both of them share with the gastric acid. Next up we have vasopressin, specifically in humans, it's arginine vasopressin, mostly with others and other animals. This again has a role with regulating blood pressure, again with the sleep weight cycle, again with urination, but also another curveball one with social bonding. And I'll get into specifically what is meant by that, because there's actually a surprising amount of nuance when it comes to what a pro-social hormone really is. And then lastly we have oxytocin, the love hormone. Although several months ago I had ranted on Twitter about how we really need to stop calling it the love hormone, there's a lot of stuff going on there that is actually pretty complicated, but oxytocin shares an effect on your urination, unsurprisingly with social bonding, and then also how you perform facial analysis. So obviously enough a lot of this is tightly tied together, but also is going to be building up on stuff we've talked about before. So to sort of summarize the general effects these hormones have, we are talking about regulating the rest and digest versus flight or flight states, not the fight-or-flight response, that would be from catecholamines like epinephrine and norepinephrine, but the state. So what I mean by that is if you're in the fight-or-flight state, you're paying more attention to what's going on, your gastrointestinal motility is down, because why would it need to be? You're more in the like, hey I'm out hunting, not hey I'm eating and you need to be moving that. You're going to be paying more attention to what's going on around you, you are going to be more tense, those kinds of things. It's the state, not the actual response. The response you'd have after something startles you or oh hey that's prey I need to start chasing down. Obviously it doesn't really apply to humans in modern society but this biology is still there, it's still relics from how things used to be. Next up is the share a lot of role in social bonding and specifically what I mean by this, because for a good while it was thought that oxytocin especially and vasopressin to a lesser extent were just kind of pro-social. The more of them you had, the more sociable you'd be and of story, actually rather nuanced. I know I do have a link down in the video description for the specific claim. Oxytocin in particular, although this was found a little bit with vasopressin, specifically how the social bonding works, is it causes you to bind more closely to your in-group or especially your romantic partner or your child and simultaneously to develop an anxiety or lack of trust towards individuals in the outgroup. Rather than just saying like pro-social, what I think is a good way to characterize the role of these hormones as far as sociality goes is that it causes you to be more group-oriented or more clique-oriented rather than more of like egalitarian everybody on equal footing. That has actually very major implications in how autism works. I'm going to finish summarizing and then I'll talk specifically in how all of this ties into autism. But then, considering what I said about how many of these have effects on gastric acid production and saliva production, there are some lesser found roles in how they have to do with gastric fertility. So that would be the parastalysis or sort of squeezing contractions that the intestines do that help move everything through your body. That is less pronounced. So this winds up leading to several issues, but primarily constipation. You can't digest your food as well, you can't move that less digested food as good through your GI tract, and constipation is an incredibly widely reported problem of autism. It got ignored for the longest time. Two of the studies that I linked down have reported rates of constipation upwards of 80%, which is extremely common. It is prevalent enough that it probably should be considered part of the diagnostic criteria. Not being constipated does not autistic. Roughly 20% don't present constipation, then you could be autistic and not constipated. But that's another one of those identifying factors that makes it clear that, okay, this person is autistic, it's not that they're like they weren't taught how to socialize properly by their parents, there's more going on here clearly. It's a useful little tip. This may, although I'm not entirely certain, be a significant part in why the autistic tend to be much more picky eaters. Although sensory things are also playing a role there, but obviously enough, you learn very well whether you're autistic or not, what foods agree with you, what ones don't, and so chances are this is a huge part of why the autistic might have picky eaters. You learn what is easier for your atypical gastrointestinal tract to still digest what isn't going to get you constipated as much. So tying these to autism in particular, I had had for a little bit, but since Delph, much more into that, the vision in particular, something a lot of people, non-autistic people have commented about autistic people and how the eyes sort of are in conversation is it's like we're not paying attention to the individual. We are. I had a girlfriend regularly, they tried to imply that I wasn't paying attention to her, and I can recite word for word what she just said to me. After a few times of that, I just kind of sunk in that like, yeah, I'm actually paying attention to you. I'm listening attentively. She had some insecurities about that too that were confounding factors, but I'm paying attention. But it's like we're constantly scanning the background, which is why it seems like we're not interested, that this often gets described as being like, oh, easily distracted, and maybe the child also has ADHD, which is possible. ADHD is legitimately seen more often with autism, but what I want to propose has been by some research, but as an alternative explanation for that, that probably explains more cases than ADHD does, is what I was just saying about how these hormones have a role in the fight-or-flight versus rest-digest states. If you are more vigilant, if you are more on guard, if you are, you know, less relaxed, you're going to be paying attention to what's going on around you. More vigilant. Not necessarily hyper-vigilant, but you are more vigilant. You're going to be scanning around for threats, not because you're necessarily in fear all the time, that fear response isn't necessarily being triggered, but you are in that more fight-or-flight state. You are more vigilant, and so it makes sense to be scanning for threats. This is almost certainly why the specific visual patterns are scanning the background behind the person being talked to and not just staring off at random things that happen to be moving around. That sounds more ADHD-like, scanning the background, or the other thing I've seen is sometimes scanning entryways or exits. It's a lot more like vigilance. Lastly, the social bonding and facial analysis. We've sort of talked about this from different perspectives in previous videos, but think about what I had said about oxytocin in particular in how it affects social bonding. Higher levels of oxytocin cause you to bind stronger to your specific partner, child, or just in general your in-group. Lower levels cause you to be more egalitarian towards everybody, not tightly fitting into your group, but being more okay with all groups. Similarly, the low levels of oxytocin that cause you to be more tightly bound to your group also cause higher levels of distrust for other groups. This is going to make it seem like autistic individuals are less devoted to the in-group, and there is some validity to that, but that's not the same thing as being a threat to the in-group. However, because of the higher levels of distrust towards people in the out-group, what winds up happening is because you are not devoted to the group, even though you are not opposed to it, you are going to be more likely to be labeled by that group as an outsider, and therefore something to be afraid of. What I am describing is the hormones responsible for the moral tribe's phenomenon and the double empathy problem. See, those aren't just supported in social psychology, they actually wind up spanning multiple different fields. Findings in endocrinology and pharmacodynamics have actually supported those social psychology phenomenon as well. This also explains numerous not diagnostically relevant attributes about the autism, about the autistic, but still very widely reported that the autistic tend to be less judgmental towards others differences, and that makes sense with what I've described about oxytocin and vasopressin because you're less group bound and more people overall. But another, yeah, I lost my train of thought. I hate when this happens, and I'm probably going to forget to edit this out of the video. I will just skip straight to the facial analysis part of that then. Oxytocin in particular, and it seems like vasopressin doesn't have this role, does alter how you do facial analysis, and particularly causes you to scan the background less and focus more on the sort of key triangle between the eyes and the mouth. The oxytocin causes you to pay more attention. Lower levels, like you see with the autistic, you tend to scan everything relatively because paying attention to the background you're being vigilant. Obviously not as good for making it look like you're paying attention to people who over not over prioritized, I feel like it's over prioritizing, but who heavily prioritized key triangle. It's very possible between the effects low levels of oxytocin has on trust of others in general, so low levels of oxytocin has a higher level of trust for people not in your in-group, so causes you to trust people in general more. We talked about that last time, but also further evidence that the trustworthiness is definitely something assessed in the face, and further backs up why this is being missed in the autistic. As you can tell, especially after this video, a lot of this stuff is not behavioral. A lot of this stuff has neurological or endocrinological hormones, or things that act like hormones, roots. This is obviously been a more medical heavy discussion, so if you need anything explained better or in different ways, please ask down in the comments, but I hopefully did a good job explaining this. Next video, what I plan on doing is talking about the fear response in particular, because it's a great segue into explaining how emotions present differently in the autistic, and unfortunate consequences of that, because a lot of the time we get told we're faking, even though it can be proven that we're not. Until then, have a good one, guys.