Autism: The Real Reason It’s Going Up

Autism rates are rising all over the world, and lots of people are wondering: why? In the U. S., HHS Secretary Robert F. Kennedy Jr. has said the cause is an "environmental toxin" and has vowed to get to the bottom of it. But we already have lots of science on this — so what does that research tell us? We talk with epidemiologist Professor Brian Lee, Associate Professor Karen Heffler, clinical psychologist Professor Catherine Lord, epidemiologist Professor Maureen Durkin, and Senior Science Researcher Dena Gassner. We want to hear your ideas for new episodes of Science Vs! Tell us via: Instagram at science_vs Bluesky at sciencevs X at @sciencevs Email at [email protected] Voicemail at +1(774) 481-1238‬ Find our transcript here: https://bit.ly/ScienceVsAutism In this episode, we cover: (00:00) Rates of autism are going up (03:33) The hunt for the cause of the ‘autism epidemic’ (13:43) Could screen time be causing autism? (20:10) The changing definition of autism (27:48) Could this explain the rise in autism? This episode was produced by Meryl Horn, with help from Wendy Zukerman, Ekedi Fausther-Keeys, Michelle Dang, and Rose Rimler. We’re edited by Blythe Terrell. Fact checking, research assistance, and consulting by Erica Akiko Howard. Mix and sound design by Bobby Lord. Music written by Emma Munger, So Wylie, Peter Leonard, Bumi Hidaka and Bobby Lord. A special thanks to the researchers we reached out to, including Professor Karen Pierce, Professor David Mandell, Professor Deborah Bilder, Professor Frédérique Bonnet-Brilhault, Dr. Helen Tager-Flusburg, Dr. Isabella de la Lara, Katherine Byrne, Professor Sven Bölte, and Dr. Whitney Worsham. Special thanks also to Lynn Keeys and Mbella Beseka, Chris Suter, Elise and Dylan, Jack Weinstein and Hunter, and Joseph Lavelle Wilson and the Zukerman Family. Science Vs is a Spotify Studios Original. Listen for free on Spotify or wherever you get your podcasts. Follow us and tap the bell for episode notifications. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Wendy Zukerman?

  Hi, I'm Wendy Zukerman and you're listening to Science Verses.

• 0:05Wendy Zukerman?

  This is our last episode for a little bit. We're going to take a short break until September while we work on new episodes. So that means if you have an idea, something that you want us to versus, you've got to tell us. There's a lot of ways to do it. You could do it on social media, Instagram, TikTok. There's an email address. It's all in the show notes. So if you've got an idea, something that we have to versus, please let us know. We absolutely love hearing from you. Now, on with the show. Today's episode is all about autism. Because we're asking, why does so many folks have it these days? Rates of autism have been going up and up for decades.

• 0:49Wendy Zukerman?

  But then, a couple of months ago, the CDC released the latest numbers, catapulting this issue into the spotlight.

• 0:57Speaker 01

  A brand new report out today from the Centers for Disease Control finds a dramatic rise in autism diagnoses among children.

• 1:05Speaker 02

  An alarming spike in the number of children diagnosed with autism. New data just released shows a 15% jump in just two years.

• 1:14Wendy Zukerman?

  The CDC report found that one in every 31 kids looked like they now had autism, which is nearly five times more common than it was 25 years ago. And the rates in boys were even higher. Health and Human Services Secretary Robert F. Kennedy Jr. says, "This is an epidemic."

• 1:33Speaker 03

  This is part of an unrelenting upward trend. Prevalence two years ago, the answer is very clear. And this is catastrophic for our country.

• 1:43Wendy Zukerman?

  And it's not just in the US. In Japan, Canada, Australia, Europe, rates of autism have been going up too. And now, there is this huge fight brewing as to what's behind this. Why do so many people have autism these days?

• 1:59Wendy Zukerman?

  RFK Junior reckons.

• 2:01Speaker 03

  This is coming from an environmental toxin. And somebody made a profit by putting that environmental toxin into our air, our water, our medicines, our food.

• 2:11Wendy Zukerman?

  There's all these different theories about what's causing this, from vaccines to pollution and a whole bunch of other stuff.

• 2:18Speaker 04

  Can more screen make your child autistic? A new study says yes.

• 2:24Speaker 05

  It might be microplastics, the forever chemicals.

• 2:27Speaker 06

  Living in an area with high levels of air pollution may be linked with a woman's chances of having a child with autism.

• 2:37Wendy Zukerman?

  But then there are folks saying, whoa, whoa, whoa, whoa. There's actually a much simpler explanation here. And it all has to do with how we diagnose autism in the first place. So who's right? What is going on here? At a recent press conference, RFK Junior said that we're going to start to have answers on the root cause of this epidemic by the end of the year. But Christmas has come early. Because today on the show, we are going to find out what's happening. When it comes to the rise in autism, there's a lot of fingers pointing at lots of different things.

• 3:10Speaker 04

  More screens.

• 3:11Speaker 05

  Toxic. Microplastics.

• 3:14Wendy Zukerman?

  But then, there's science.

• 3:19Wendy Zukerman?

  Science versus Autism is coming up just after the break.

• 3:29Speaker 07

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• 4:59Wendy Zukerman?

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• 5:40Wendy Zukerman?

  Welcome back. Today, we're looking at autism and finding out why the numbers of people being diagnosed with it have been going up and up. To tell us all about it, we have senior producer Meryl Hord. Hey, Meryl.

• 5:55Speaker 07

  Hey, Wendy.

• 5:56Wendy Zukerman?

  All right, Meryl, can you just tell me, what exactly is autism? I just feel like people kind of throw it around, diagnosing they're friends with it, they're friends, children with it. You know what I mean? What are we talking about here?

• 6:12Speaker 07

  Well, it can show up for different people in different ways. But generally, a lot of autistic people... People will have a harder time communicating. So that's a a big theme. Um, and then there's other stuff that shows up a lot, too. Like, you might have really specific intense interests or a harder time when your routine is disrupted or more intense reactions to really annoying stimuli, like really bright lights or loud noises, that that kind of a thing.

• 6:43Wendy Zukerman?

  Uh huh. And then our big question of this episode is why do so many more people have it these days?

• 6:50Speaker 07

  Yeah, what is going on? When I started talking to scientists about about autism in general, about what causes autism, there is one thing that came up right away. Genetics is sort of the elephant in the room that you can't ignore. Genetics.

• 7:04Wendy Zukerman?

  Yeah.

• 7:06Speaker 07

  So this is Professor Brian Lee, epidemiologist at Drexel University. And he said that a huge part of whether somebody will be autistic is just passed down to you. It's in your genes.

• 7:18Wendy Zukerman?

  Hmm.

• 7:18Speaker 07

  And we know this from looking at studies on families. So like if we know if one sibling has autism, the other siblings are more likely to also have it. And then if you look at identical twins, who basically have, you know, the same DNA, it's like even more likely that if one identical twin has it, the other one is really likely to have it, too. And so based on all that, scientists have kind of figured out how much of autism is inherited. And it's Somewhere between 70 and 90%. Whoa, that's huge. Uh, yeah. 70 to 90%. Yeah, yeah. And we don't really know, like, all of the genes that are involved. Like, sometimes it might be that there are like hundreds of genes that are kind of all working together to up that chance

• 8:03Speaker 07

  that someone will have autism. Other times, it'll just be like one particular kind of genetic quirk.

• 8:09Wendy Zukerman?

  Mm hmm.

• 8:09Speaker 07

  But yeah, it's genetics is huge.

• 8:12Wendy Zukerman?

  Uh huh. I guess in the context of this rise in numbers that we're seeing though, genetics can't explain why so many folks would be diagnosed with autism now, right? I mean, because why would we suddenly have so many more autism genes in the population?

• 8:31Speaker 07

  Well, actually, there is one thing that's changed. So parents are having kids at older ages now. And that might be introducing genetic changes. That can like up the chance that their kids will be autistic.

• 8:47Wendy Zukerman?

  And so older, how, how, how old are we talking here?

• 8:50Speaker 07

  Well, Brian has studied this and so he did like a back of the envelope calculation with the latest numbers for me. Okay, so overall in the US, about 3.2% of kids are autistic. So that's kind of like the baseline chance on average for autism.

• 9:09Wendy Zukerman?

  Yeah, so one in 31 kids.

• 9:11Speaker 07

  Yeah, it works out to 3.2%.

• 9:13Wendy Zukerman?

  Okay.

• 9:14Speaker 07

  But if you're a mom over 40, we think that the chance goes up from 3.2% to something like 5.6%.

• 9:23Wendy Zukerman?

  Mm hmm, that's not nothing. And then what about, what about the other side of this, the sp- the sperm?

• 9:29Speaker 07

  It's actually a smaller increase for, for the dads, but yeah, it still goes up a little bit.

• 9:34Wendy Zukerman?

  Uh huh. So could this explain why we're seeing higher rates of autism across the country and around the world?

• 9:41Speaker 07

  Well, a lot more people are having kids later in life. Like the, the percentage of births to women who are older than 40 has basically tripled since 1990. But overall, it's still a really small percentage of like total births. It's like 4% of, of all the births in the US are from moms in their 40s. So it, I asked Brian, like at the end of the day, how much does he think this older parent thing can really explain the increase in autism cases?

• 10:11Speaker 05

  It's certainly going to contribute some, some portion, but it's, it's not explaining the lion's share.

• 10:18Wendy Zukerman?

  It's not going to explain the lion's share. Okay. So what else could explain the lion's share? We've got like the meerkat's share covered. Lion's share still out the open.

• 10:33Speaker 07

  Right. So that's the big question. Because yeah, genetics might like kind of set the stage for whether or not someone will have autism, but there is this idea that maybe you need like a trigger to actually make it happen.

• 10:45Wendy Zukerman?

  Mm hmm.

• 10:46Speaker 07

  And scientists have been finding lots of things that might sort of be that trigger and up the chance that someone will have autism. A lot of the things we're finding kind of come into play when someone's a fetus. So things that happen during pregnancy and utero. So like if a mom gets an infection, if there's birth complications, taking certain medications while you're pregnant, like there's an anti-seizure medication that will up the chance that someone will have autism. But like, a lot of that stuff doesn't really explain why autism would suddenly be more common in the last few decades, right?

• 11:21Wendy Zukerman?

  Oh, because pregnant folks aren't taking more of those meds?

• 11:25Speaker 07

  No, yeah, experts told me they didn't think that this stuff would make a huge dent. There's maybe one exception to this, which is that if you're born prematurely, like very prematurely, you're more likely to have autism. And there are more premature babies that survive now.

• 11:43Wendy Zukerman?

  Hmm.

• 11:43Speaker 07

  So maybe that's contributing a little bit to the rise. But the researchers I've talked to say that like, oh no, this is such a small proportion of people with autism that like, that, that really can't explain these huge rises that we are seeing either.

• 12:01Wendy Zukerman?

  Okay, so then what about these things in our environment? The stuff, I guess RFK Jr. talks about environmental toxins, which he said could be in our air or, or our medicines. And I suppose we could put plastics in there too? What do we know here?

• 12:19Speaker 07

  Yeah, we asked RFK's team about what specific environmental toxin he was talking about, and a spokesperson told us that, quote, "Everything is on the table." So I asked. Brian about this. When RFK Junior was talking about why autism is so pervasive, he said, quote, "This is coming from an environmental toxin." What do you make of that?

• 12:44Speaker 04

  I know of his weird conspiracy theory type attitudes on vaccines. And I'm wondering if that's code for we need to do another vaccine study. And if that's what he means, I would be very horrified because that would be a tremendous waste of money to go basically beating a dead horse at this point. Vaccines do not cause autism, full stop.

• 13:11Wendy Zukerman?

  It has been studied. It has been taken seriously. It has been studied. And, you know, various different vaccines, various ingredients in vaccines. And no, we cannot see a link here. But there are other potential things that are in our air and our water that probably weren't 25 years ago, right?

• 13:30Speaker 07

  Yeah, no. And there is a lot of research looking into other stuff that, you know, is in our environment and might be linked to autism. Brian said that one kind of hot area of research is air pollution.

• 13:42Wendy Zukerman?

  Uh huh.

• 13:42Speaker 07

  Like, a big review just found that there might be a link between being exposed to certain types of air pollution during pregnancy and the kid later having autism.

• 13:53Wendy Zukerman?

  Oh, how would that happen?

• 13:54Speaker 07

  So pollution are these tiny little particles, right, that we breathe in. And it could be that they're getting past the placenta and into the brain as it's developing. And then maybe kind of changing the brain, like maybe through oxidative stress or neuroinflammation. But the kind of pollution that's linked to autism has generally been going down over the last couple decades in the US.

• 14:21Wendy Zukerman?

  Oh.

• 14:22Speaker 07

  So like, that doesn't explain why it's been going up. And it's sort of similar with heavy metals, which is something a lot of people on the internet are worried about right now. There is some research that says maybe getting exposed to lead, for example, might up the odds for autism. But lead and other heavy metals have generally been going down.

• 14:44Wendy Zukerman?

  Oh, okay. So plastics, plastics have been going up, right?

• 14:50Speaker 07

  Yes, plastics have been going up. And there are a lot of stuff. Studies that have looked at a potential link between plastics and autism.

• 14:57Wendy Zukerman?

  Uh huh.

• 14:58Speaker 07

  So researchers will look at the blood or pee from a pregnant person and look for chemicals like phthalates or PFAS or forever chemicals.

• 15:08Wendy Zukerman?

  Uh huh.

• 15:09Speaker 07

  And then they'll ask, like, are the kids who are exposed to more of this stuff in utero, are they more likely to show signs of autism later after they're born?

• 15:18Wendy Zukerman?

  Yeah, yeah, yeah. And what did they find?

• 15:21Speaker 07

  A few studies say yes, but the vast majority of them find no connection.

• 15:27Wendy Zukerman?

  Hmm, so, okay. There's no smoking gun here thus far for the lion's share because maybe increases cases here or there, but we are looking for something that could really explain like quite a large number of people now being diagnosed with autism that were not before. Screens is the other thing being thrown out. What do we know here?

• 15:55Speaker 07

  Yeah, I looked into screens and was surprised that there actually was some research on this.

• 16:01Wendy Zukerman?

  Why?

• 16:01Speaker 07

  I don't know. People blame everything on screens and I was just like, eh, I don't really buy it. But then like, let me tell you what happened, though, when I talked about it with this researcher.

• 16:12Wendy Zukerman?

  Uh huh. I'm Karen Heffler. I'm a researcher at Drexel University.

• 16:17Speaker 07

  And unlike me, Karen was like, well, it actually makes total sense to look into screens, particularly when you look at the timeline here.

• 16:25Wendy Zukerman?

  How has the world changed over this period of time? Babies, children, used to be first exposed in the 70s at about four years of age. That's the first time they watched any television. By about 2006, it was at four months of age.

• 16:40Speaker 07

  But it's not just that the timing fits here. There is some evidence linking screens to autism. Like, there are studies that have found that kids who are exposed to more screen time when they're really little, maybe like a few hours every day when they're one or two, those kids are more likely to either show autistic traits later or even be diagnosed with autism later in life.

• 17:05Wendy Zukerman?

  Hmm, and that's not that much. Screen time, one or two hours, right?

• 17:10Speaker 07

  Yeah, like some studies find even that much might make a difference. And then Karen did this really interesting pilot study, looking at whether getting families to like, cut down on screen time might decrease their autism symptoms.

• 17:26Wendy Zukerman?

  Right.

• 17:27Speaker 07

  It was really, really tiny, so they only had nine families.

• 17:30Wendy Zukerman?

  Uh huh.

• 17:30Speaker 07

  But I thought it was interesting because the, what they had them do was pretty dramatic. So they chose families with autistic kids who were watching a lot of screen time. So before the study started, the screens were on for an average of five and a half hours every day.

• 17:46Wendy Zukerman?

  Wow, yeah.

• 17:47Speaker 07

  Then during the study, it was six months long, they got them to cut it down to like, five minutes of screen time a day.

• 17:54Wendy Zukerman?

  Not even a full episode of Bluey.

• 17:56Speaker 07

  No, exactly.

• 17:59Speaker 07

  And so she looked to see if this had an effect, and it seemed like it did work. Like, the kids had a decrease in some autism-related behaviors by the end of the study. Specifically in social skills and repetitive behaviors. So before the study. The children, at the beginning, a lot of them didn't really pay attention to their parents. They might be spinning wheels on a car, or lining up items, or just distracted with sensory, like flapping, or looking at lights, not really interested. And then after basically no screen time? The eye contact got better, they wanted to be with the parents, they started paying attention to people.

• 18:43Wendy Zukerman?

  Hmm, that feels promising.

• 18:47Speaker 07

  Yeah, but then Karen told me about something that, that really changed the way that I thought about the study.

• 18:54Wendy Zukerman?

  Uh huh.

• 18:55Speaker 07

  So, cutting down on screens was a big part of the study. But it wasn't just turning off the screens. We met with them for one hour every week, and worked on strategies to help them engage their children socially. So, eye contact.

• 19:13Speaker 07

  So if a baby coos or babbles, then the parent would smile back or maybe, you know, imitate the child. Or we would suggest that they hold interesting items to their children up to their eyes. And if the child looked at them, then say, oh, great looking. Oh, I love to see your eyes. Really positive reinforcement.

• 19:36Wendy Zukerman?

  And so from other studies, do we know that that kind of positive reinforcement with a kid with autism helps them? Like, would you expect to see these results if you forget the screenshot and you just do the positive reinforcement?

• 19:53Speaker 07

  Yes. I have a very satisfying study for you now because Karen told me about a study where they basically did that.

• 20:00Wendy Zukerman?

  Oh, OK.

• 20:01Speaker 07

  So this one was a larger, proper randomized controlled trial with about 100 really young kids. And they had started to show some signs of autism. And what they did in the trial kind of reminded me of a lot of the things that Karen did in her study because it was like teaching the parents how to pay attention to their kids really closely responding to them and interacting with them.

• 20:25Wendy Zukerman?

  Right.

• 20:25Speaker 07

  But they didn't tell them anything to do with screens.

• 20:28Wendy Zukerman?

  Perfect. Great. OK. So then what happened?

• 20:31Speaker 07

  Well, fewer of those kids were diagnosed with autism later.

• 20:35Wendy Zukerman?

  So then, so what do you think? How much do you think screens are playing a role here in this so-called autism epidemic?

• 20:42Speaker 07

  Well, it is a little tricky because like there are also other explanations why we might see a link between screen time and autism.

• 20:50Wendy Zukerman?

  Right.

• 20:51Speaker 07

  Like, we know that a lot of kids who are autistic really enjoy watching screens. So maybe it's just that someone's already autistic and then maybe their parents like put the TV on more for them because they see that they're really happy. But like, that's not to say that screens are totally innocent here because like you can also imagine that like maybe there's a kid who is already on the autism spectrum. Is watching like hours and hours of screen time every day instead of interacting with other people. Maybe they're more likely to end up with an autism diagnosis because their social skills aren't getting like a workout.

• 21:27Wendy Zukerman?

  Hmm, that makes sense. But I think bottom line, you don't seem to think there's evidence that screens are really behind this, this epidemic, you know?

• 21:40Speaker 07

  Maybe a little bit, but it's really hard to say how much.

• 21:43Wendy Zukerman?

  Okay, so here's where we're at. I don't know, I feel like we have not gotten that lion's share of these cases yet. I mean, there's more meerkat dinners here and there, but we're missing something big still.

• 22:01Speaker 07

  Yeah, yeah, that's what we're gonna look at after the break. Something big.

• 22:14Speaker 07

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• 24:05Wendy Zukerman?

  Welcome back. Today on the show, Autism: What Is Causing the Rise in Cases? We talked about how there's a lot of things people are pointing the finger at from plastics, which is maybe it plays some role here, but it's definitely not a slam dunk. Vaccines are a no, screens are a maybe. People having kids when they're older, playing some role here, but not that much. Merrill, you've promised me something big.

• 24:34Speaker 07

  Yeah.

• 24:34Wendy Zukerman?

  The lion's share. I feel like we've earned it.

• 24:38Speaker 07

  Yes. Well, so one idea is that this actually just has to do with the way we're deciding who has autism and who doesn't.

• 24:48Wendy Zukerman?

  Uh huh. And that basically we've decided a whole lot more people who would otherwise not be classified as having autism now, all of a sudden, eh, you can join the party as well.

• 24:59Speaker 07

  Yeah, yeah. And this is something that RFK Junior really rallied against in his speech. He said that the idea that we are somehow not catching all these cases in the past is actually insulting to the doctors who were practicing back then.

• 25:15Speaker 03

  Doctors and therapists in the past were not stupid. They weren't missing all these cases. The epidemic is real.

• 25:24Speaker 07

  So to get to the bottom of this, I decided to call up a scientist who has been diagnosing autism for decades. This is Catherine Lord, professor at UCLA.

• 25:33Wendy Zukerman?

  Did you ask her if she was stupid?

• 25:36Speaker 07

  Yeah, that was my first question. But actually, my first question was about something else.

• 25:43Wendy Zukerman?

  Okay. I was told by one of your colleagues that you are the diagnostic queen when it comes to autism. Oh, dear. Well, I, with other people, not single-handedly.

• 25:56Speaker 07

  By any means, I worked to develop the most commonly used diagnostic instruments that people use when they diagnose autism. That's where that came from.

• 26:07Wendy Zukerman?

  She's also the diagnostic queen because she's been in this field through the like absolutely wild changes that have happened over the past few decades when it comes to how we do this, how we diagnose autism, which Uh huh. I know it kind of sounds like a snooze fest, but it's, you know, it's actually the story of like how our understanding of what autism is has evolved. So let's start in the 1960s. Back then, we weren't even sure if autism was its own thing or if it was part of schizophrenia. Oh. And this is kind of what we thought autism looked like then.

• 26:49Speaker 07

  I mean, I think in the 60s, a person with autism would often be not verbal, like not talking and would be quite severely intellectually disabled. We were very focused on things like flapping your hands and looking at your fingers and the things that you can see right away.

• 27:08Wendy Zukerman?

  This is when Catherine got into the field as an undergrad and she loved working with autistic kids and finding ways to connect with them, even, you know, when they weren't verbal. But then sometimes a kid would come in who would really challenge the idea of what someone with autism was like. Like Catherine remembers this one kid.

• 27:28Speaker 07

  Oh, I saw this little boy who had all kinds of language that just poured out of him. And in those days, we had them, parents, sit in another room and watch us. And so he was not happy about that at all. He was about four and he had a lot of repetitive language and his nose was running. And he started talking about, I don't want to be a rainbow. I don't want to be a reindeer. I don't want to be a reindeer, running reindeer. I don't want to be a reindeer. And what he was talking about was he was crying and his nose was running and he had these phrases and he was trying to figure out how to say, you're making me cry.

• 28:14Speaker 07

  And people were like, boy, I don't know if he could. Be autistic and he was as autistic as you could be.

• 28:22Wendy Zukerman?

  So what made him, what else about him made it clear that he had autism?

• 28:28Speaker 07

  Well, now we know that like, it's not necessarily that you don't have any language at all, but you know, the way he used language was really different. Like, he would often repeat phrases over and over again. And so, yeah, it's like not as simple as, as we thought. And so that was the 1960s, but that's kind of like limited definition of autism stuck around for a really long time.

• 28:52Wendy Zukerman?

  That you needed these severe traits?

• 28:54Speaker 07

  Yeah, like really severe traits and it was often accompanied by intellectual disability.

• 29:01Speaker 07

  But then, even in 1980, this is when you see autism get its own entry in the DSM, which is the like bible for diagnosing psychiatric conditions. So now it's like, it's not part of schizophrenia anymore. We got that right. But the description of autism is pretty intense. Like it says, quote, "This disorder is extremely incapacitating," unquote. But then, there's kind of a turning point. The next version of the DSM comes out in 1987. So by then, scientists had started to think about autism as like a looser kind of collection of traits. Like, we still think that having trouble communicating is like a hallmark of autism.

• 29:44Speaker 07

  But maybe it's also that you're really interested in a specific thing. So getting very focused on something, you know, that could be anything. I mean, it could be the same things other kids are interested in, so, you know, dinosaurs. But it also could be Scottish clans. Or we had somebody who loved newspaper editors. He was an expert on who were the editors of the major newspapers and could recite that. So it's, it's, and it's not bad to have an interest. It's just that not being able sometimes to, to rein it in if other people are not so interested.

• 30:23Wendy Zukerman?

  So this is, I mean, the late 80s is exactly when Rain Man came out.

• 30:27Speaker 07

  Yeah.

• 30:28Wendy Zukerman?

  Right. And I mean, I'm sure with 2025 eyes, that movie does not hold up well. But it does show how much the image of autism, at least in the public's imagination, changed so much already by then. You know, he was a character that was a genius in some respects. I mean, like, he could memorize the phone book, right?

• 30:54Speaker 07

  Yeah, and just generally, we end up getting to this place where just because you're autistic doesn't mean that you're incapacitated, like it used to be described. Like, in some cases, you might be better at things than neurotypical people.

• 31:10Wendy Zukerman?

  And so we can see this expanding and expanding definition of autism.

• 31:17Speaker 07

  And there you also, kind of going along with this, we used to think that Asperger's Syndrome was something different.

• 31:23Wendy Zukerman?

  Right. Oh, yeah.

• 31:25Speaker 07

  And now that's been rolled right up into autism spectrum disorder. It's all part of the same thing.

• 31:30Wendy Zukerman?

  Uh huh. Okay.

• 31:31Speaker 07

  But I feel like this idea of what autism is, is still changing right now. It's like the tectonic plates are still shifting and in, you know, another 50 years, it could just look different again.

• 31:43Wendy Zukerman?

  So what, what is the sort of suggestion here is that this autism epidemic, these new cases of autism, it's actually just because we have changed our definition of autism. We're not just capturing these folks who have a real difficulty verbalizing, communicating, maybe also happen to have severe intellectual disability. We're now opening up the definition to include folks who are neurodivergent in more subtle ways.

• 32:19Speaker 07

  Yeah.

• 32:20Wendy Zukerman?

  And but that, that would mean you should be able to see that in the data, right? And yet RFK Junior says that most of the new cases are, quote, severe, which would go against this idea that, oh, it's just our changing diagnosis, right?

• 32:36Speaker 07

  Yeah, he's kind of like, no, now is when we're seeing all these severe cases. Like, he painted this really dark picture where he called this a tragedy and said that, Autism destroys families.

• 32:49Speaker 03

  Most cases now are severe. So about 25% of the kids who are diagnosed with autism are nonverbal, non-toilet trained.

• 33:00Speaker 07

  And yeah, that's like in pretty stark contrast to this idea that autism is actually just going up because of this definition kind of expanding.

• 33:09Wendy Zukerman?

  Yeah. So who's right? I mean, do we, do we have any numbers here?

• 33:13Speaker 07

  So a couple of researchers told me like, oh, you have to talk to Maureen Durkin because you just presented this work at this huge autism conference that looks at that exact question.

• 33:23Wendy Zukerman?

  Oh, cool.

• 33:24Speaker 07

  So yeah, she's an epidemiologist at the University of Wisconsin-Madison. Hi, Maureen. Can you hear me okay? Hi, I can hear you great. So Maureen basically found a new way to like dig into the data to look at what kind of kinds of autism cases are the ones that have been going up.

• 33:41Wendy Zukerman?

  Great, great.

• 33:42Speaker 07

  So she did this, um, these are eight-year-old kids from across the country and the, the kind of timeframe she's looking at was from 2000 to 2016. And what she does is kind of divide autism cases up into different buckets where on one end you have what people might think of as like severe autism. So this is somebody who needs a lot of help when it comes to stuff like going to the bathroom, getting dressed, communicating their needs, that kind of thing. They're like day-to-day functioning.

• 34:13Wendy Zukerman?

  Yeah.

• 34:14Speaker 07

  And so actually, let's start there and find out like what Maureen saw when she looked at those kids over time. This group.

• 34:21Wendy Zukerman?

  Did not increase at all.

• 34:23Speaker 07

  It did not?

• 34:24Wendy Zukerman?

  In fact, it declined a slight bit.

• 34:25Speaker 07

  Whoa.

• 34:26Wendy Zukerman?

  But it didn't increase. Did not increase. Mm-hmm.

• 34:32Speaker 07

  And when she looked at what cases were going up, it was a totally different group of kids.

• 34:38Wendy Zukerman?

  The biggest increase was in those with no actual measurable functional limitations.

• 34:43Speaker 07

  Oh.

• 34:44Wendy Zukerman?

  Yeah. The biggest increase was in that group because that was a very small group in 2000. Hmm.

• 34:52Speaker 07

  Yeah, so.

• 34:53Wendy Zukerman?

  Right.

• 34:54Speaker 07

  So these are kids who are autistic, who don't actually need any more help than neurotypical kids in their day-to-day life. And then Maureen also saw a rise in kids who maybe need like a little bit more help. And this research isn't out in a journal yet. It's in peer review now. But she presented it at this conference. So let me show you this, this graph that she presented there. That kind of made a big splash.

• 35:18Wendy Zukerman?

  Uh huh.

• 35:20Speaker 07

  So this is looking over time from 2000 to 2016.

• 35:24Wendy Zukerman?

  Oh, yeah. And you can see really clearly that the severe cases, they have dropped a tiny bit, maybe barely statistically significant, she got the error bars there. But it's really these milder forms. That's what's, that's the lion's share, Merrill.

• 35:45Speaker 07

  Yeah. We found it.

• 35:47Wendy Zukerman?

  We found it. We found it.

• 35:51Speaker 07

  So I asked Maureen. And so these were the cases that we were kind of missing decades ago.

• 35:56Wendy Zukerman?

  It appears that. Well, we know that's true, that, that as the definition of autism has expanded over time, we're including a wider spectrum.

• 36:06Speaker 07

  We did reach out to RFK's team to ask them what they made of this research. They didn't address that question, but instead they doubled down on the idea that there is an environmental toxin that's causing this. I also asked Catherine Lord about this.

• 36:22Wendy Zukerman?

  If we are labeling more people today with this label, how much does that really matter when it comes to explaining why it looks like autism has gone up? I mean, I think it accounts for most of it. And I think all of us worry that we're consuming plastics and things that we, you know, that we wouldn't choose to eat or, or breathe. But that can't account for most of what's gone on. So in a press conference recently, Health and Human Services Secretary Robert F. Kennedy Jr. basically kind of pooh-poohed this idea that it is just about changing diagnosis. So is he wrong, basically? Yeah, I think he's wrong.

• 37:06Speaker 07

  And there are other things that might explain why we're seeing more and more cases of autism. Like it's become standard to screen kids when they go to the pediatrician for autism. There's also just more awareness. A lot of researchers told me they think that could be playing a role here.

• 37:23Wendy Zukerman?

  Right, yeah.

• 37:24Speaker 07

  And that leads me to the final thing I wanted to mention. Because like now that we've got this bigger understanding of autism, of what it can be, it's really shifted the picture of what an autistic person could look like. So in the past, there was a strong bias towards diagnosing boys with autism.

• 37:44Wendy Zukerman?

  The hardest thing was that if you're female, you're not autistic because it's very, very rare.

• 37:49Speaker 07

  So this is Dena Gassner, researcher at Drexel University. And yeah, she told me that she's autistic and she wasn't diagnosed until she was 40. And she said that for so long, doctors had this idea that autism was pretty rare in girls. Where today, you see that ratio sort of leveling out. And it also used to be more common to get diagnosed with autism if you were white. But those numbers are also leveling out. So now in the US, white kids are not more likely to be diagnosed with autism compared to other racial groups.

• 38:22Wendy Zukerman?

  Hmm.

• 38:22Speaker 07

  And it's not necessarily that, you know, these people weren't getting any diagnosis at all. In a lot of cases, they were getting misdiagnosed with something else. This happened to Dina.

• 38:34Wendy Zukerman?

  I was misdiagnosed with bipolar.

• 38:36Speaker 07

  Oh, wow.

• 38:37Wendy Zukerman?

  And that is not uncommon. Bipolar and personality conditions are often diagnosed in autistic women before they get their right diagnosis. And the problem with that is the medications that come with that.

• 38:51Speaker 07

  Yeah, so for Dina, even though she never had bipolar, she was put on lithium. What did the lithium feel like?

• 38:58Wendy Zukerman?

  Oh, I was completely dysfunctional, you know, I could not, I just wasn't a human being for that timeframe. And so I finally found a doctor who was actually treating my children, who said, I think you might want to reevaluate where you are. And he saved my life. Gosh.

• 39:18Speaker 07

  Yeah, researchers have told me that this is, this is actually kind of a common thing that, you know, a parent will take their kid in to get diagnosed with autism and then they'll walk away with their own diagnosis. That was missed years ago.

• 39:30Wendy Zukerman?

  Oh, right. Which goes back to this idea that genetics is so important. So this epidemic that we're seeing, because now instead of one case, you have two cases.

• 39:39Speaker 07

  Yeah, but you know, like, it's funny, we keep using that word epidemic to describe what's going on. And I don't think that's actually the right word to describe, like, the rising cases. I mean, lots of scientists have told me that, like, the real epidemic here is that we are failing so many autistic people who need better services, that there's an epidemic there. But the idea that the rising cases is in and of itself a tragedy or an epidemic. I asked Dina about that. How do you feel about the fact that we're seeing more and more people being diagnosed with autism today?

• 40:14Speaker 05

  I think it's fantastic.

• 40:15Speaker 07

  Yeah, so for Dina, it was like the start of really understanding who she was, and also helped her find a community of other autistic people, and also other moms of autistic kids, since her son is autistic, too.

• 40:29Speaker 05

  I was seeing that mothers of autistic kids were often abandoned by their girlfriend network. And we need nurturing, and we need community. And so I started a group called Margarita Moms. And we drank margaritas, and we went to see Magic Mike. And, you know, and our rule was, you're not allowed to talk about your child, but you can talk about your undiagnosed husband, you know? And, you know, and we had fun. And so we're seeing this, this rising, you know, army of these really neurodivergently intact, healthy, well-adjusted

• 41:11Speaker 05

  autistic kids that are coming up. And my grandma jeans get all fired up. Like, I'm like, oh, that's so awesome. Let me see your child dancing to Taylor Swift. It's joy. It's autistic joy that's coming out of this newer population. And so that's why much of our community is pushing back on these highly stigmatizing languages, you know, assigning tragedy mindsets to this population. When we experience access to community...

• 41:43Wendy Zukerman?

  Communication, unconditional love and meaningful usable supports. We have healthy, well-adjusted but autistic people. And that's a good thing.

• 41:56Wendy Zukerman?

  Yeah. Well, we've solved the case of the so-called autism epidemic.

• 42:02Speaker 07

  Yep.

• 42:03Wendy Zukerman?

  Merry Christmas. Thanks, Meryl.

• 42:06Speaker 07

  Thanks, Wendy.

• 42:07Wendy Zukerman?

  That's science versus.

• 42:11Wendy Zukerman?

  So the science versus is going to be on a little break until September while we work on new episodes. And I thought to celebrate this last episode of the season, I would invite the team to our citations chat.

• 42:27Speaker 07

  Yay.

• 42:28Wendy Zukerman?

  Hi, everyone. Hi.

• 42:31Speaker 07

  No. And a baby.

• 42:34Wendy Zukerman?

  And a baby's here, too. How many citations are in this week's episode?

• 42:38Speaker 07

  Sixty. Sixty.

• 42:42Wendy Zukerman?

  Akadi, what was your favorite moment of the season? I think my favorite moment of the season has to be meth. Ooh, meth. I just like, it's my new vocal stem. I say it at least like a couple of times a week for sure. So. Michelle, favorite moment? I really loved bird flu and learning about manure lagoons. That was just the weirdest fun fact in the world. Fun. I just have to pick the fact that we finally made our episode on squirting. Of course. It was just a delight and it was a long time coming. Ooh. Meryl? I have to say the carnivore diet episode last week was just so fun.

• 43:27Wendy Zukerman?

  Something about the top, it was just so like bro-y and hardcore. I just like, it really made my dopamine flow. All right, then to cap us off for this season, we'll be back in September. Ways to get in touch to pitch us ideas are all in the show notes. Please do that. The citations link to the transcript, it's also in the show notes. But to cap us off, all right, everyone, let's say primal. Primal.

• 43:54Speaker 07

  Primal.

• 43:58Wendy Zukerman?

  Is there a better word? Is there a better science word?

• 44:00Speaker 07

  Peer-reviewed literature.

• 44:04Wendy Zukerman?

  Thank you so much for listening and we will see and you will hear us very, very soon. Thanks, guys. Bye, boy, boy. Bye. Bye.

• 44:21Wendy Zukerman?

  This episode was produced by Merrill Horn, with help from me, Wendy Zukerman, Ekati Foster-Keeys, Michelle Dang, and Rose Rimla. We're edited by Blythe Terrell. Fact checking, research assistance, and consulting by Erica Akiko Howard. Mix and sound design by Bobby Lord. Music written by Emma Munga, So Wiley, Peter Leonard, Bumi Hidaka, and Bobby Lord. A special thanks to the researchers that we reached out to, including Professor Karen Pierce, Professor David Mandell, Professor Deborah Bilder, Professor Frederic Bonnet-Brio, Dr. Helen Tager-Flusburg, Dr. Isabella Delalara, Catherine Byrne, Professor Sven Bolte, and Dr. Whitney Worsham. Special thanks also to Lynne Keys, Anne Bella Vaseka,

• 45:06Wendy Zukerman?

  Chris Suter, Elise and Dylan, Jack Weinstein and Hunter, Joseph Lavelle-Wilson, and the Zukerman family. Science Versus is a Spotify Studios original. Listen to us for free on Spotify or wherever you get your podcasts. We are everywhere. If you are listening on Spotify, then follow us and tap the bell icon so you get notifications when new episodes come out. We'll be back in your ears in September. And I'm Wendy Zukerman, and I'll be back to you then.

• 45:47Speaker 07

  From the creators of Zootopia and Frozen comes Disney's Hext. Welcome to Hext and enter the world of witchits, where it was foretold that an ordinary girl would become an extraordinary witch and save the world of magic. Disney's Hext arrives in theaters this Thanksgiving.

• 46:06Speaker 03

  Now streaming on Paramount+. I'm Dexter Morgan. I've been killing killers for half my life. It gets to you. You're having a midlife crisis. I'm not ready for this. He's back. I'm older. I'm wiser. And sharper than ever. Things are gonna get messy. But if I can't believe in myself, I can't believe in anything. Dexter Resurrection. New season now streaming on the Paramount+ Premium Plan.