Why Are Autism Rates Steadily Rising?
Stefania Sterling was just 21 when she had her son, Charlie. She was young and healthy, with no genetic issues apparent in either her or her husband's family, so she expected Charlie to be typical.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period."
It wasn't until she went to a Mommy and Me music class when he was one, and she saw all the other one-year-olds walking, that she realized how different her son was. He could barely crawl, didn't speak, and made no eye contact. By the time he was three, he was diagnosed as being on the lower functioning end of the autism spectrum.
She isn't sure why it happened – and researchers, too, are still trying to understand the basis of the complex condition. Studies suggest that genes can act together with influences from the environment to affect development in ways that lead to Autism Spectrum Disorder (ASD). But rates of ASD are rising dramatically, making the need to figure out why it's happening all the more urgent.
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Indeed, the CDC's latest autism report, released last week, which uses 2016 data, found that the prevalence of ASD in four-year-old children was one in 64 children, or 15.6 affected children per 1,000. That's more than the 14.1 rate they found in 2014, for the 11 states included in the study. New Jersey, as in years past, was the highest, with 25.3 per 1,000, compared to Missouri, which had just 8.8 per 1,000.
The rate for eight-year-olds had risen as well. Researchers found the ASD prevalence nationwide was 18.5 per 1,000, or one in 54, about 10 percent higher than the 16.8 rate found in 2014. New Jersey, again, was the highest, at one in 32 kids, compared to Colorado, which had the lowest rate, at one in 76 kids. For New Jersey, that's a 175 percent rise from the baseline number taken in 2000, when the state had just one in 101 kids.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period," said Walter Zahorodny, an associate professor of pediatrics at Rutgers New Jersey Medical School, who was involved in collecting the data.
The study echoed the findings of a surprising 2011 study in South Korea that found 1 in every 38 students had ASD. That was the the first comprehensive study of autism prevalence using a total population sample: A team of investigators from the U.S., South Korea, and Canada looked at 55,000 children ages 7 to 12 living in a community in South Korea and found that 2.64 percent of them had some level of autism.
Searching for Answers
Scientists can't put their finger on why rates are rising. Some say it's better diagnosis. That is, it's not that more people have autism. It's that we're better at detecting it. Others attribute it to changes in the diagnostic criteria. Specifically, the May 2013 update of the Diagnostic and Statistical Manual of Mental Disorders-5 -- the standard classification of mental disorders -- removed the communication deficit from the autism definition, which made more children fall under that category. Cynical observers believe physicians and therapists are handing out the diagnosis more freely to allow access to services available only to children with autism, but that are also effective for other children.
Alycia Halladay, chief science officer for the Autism Science Foundation in New York, said she wishes there were just one answer, but there's not. While she believes the rising ASD numbers are due in part to factors like better diagnosis and a change in the definition, she does not believe that accounts for the entire rise in prevalence. As for the high numbers in New Jersey, she said the state has always had a higher prevalence of autism compared to other states. It is also one of the few states that does a good job at recording cases of autism in its educational records, meaning that children in New Jersey are more likely to be counted compared to kids in other states.
"Not every state is as good as New Jersey," she said. "That accounts for some of the difference compared to elsewhere, but we don't know if it's all of the difference in prevalence, or most of it, or what."
"What we do know is that vaccinations do not cause autism."
There is simply no defined proven reason for these increases, said Scott Badesch, outgoing president and CEO of the Autism Society of America.
"There are suggestions that it is based on better diagnosis, but there are also suggestions that the incidence of autism is in fact increasing due to reasons that have yet been determined," he said, adding, "What we do know is that vaccinations do not cause autism."
Zahorodny, the pediatrics professor, believes something is going on beyond better detection or evolving definitions.
"Changes in awareness and shifts in how children are identified or diagnosed are relevant, but they only take you so far in accounting for an increase of this magnitude," he said. "We don't know what is driving the surge in autism recorded by the ADDM Network and others."
He suggested that the increase in prevalence could be due to non-genetic environmental triggers or risk factors we do not yet know about, citing possibilities including parental age, prematurity, low birth rate, multiplicity, breech presentation, or C-section delivery. It may not be one, but rather several factors combined, he said.
"Increases in ASD prevalence have affected the whole population, so the triggers or risks must be very widely dispersed across all strata," he added.
There are studies that find new risk factors for ASD almost on a daily basis, said Idan Menashe, assistant professor in the Department of Health at Ben-Gurion University of the Negev, the fastest growing research university in Israel.
"There are plenty of studies that find new genetic variants (and new genes)," he said. In addition, various prenatal and perinatal risk factors are associated with a risk of ASD. He cited a study his university conducted last year on the relationship between C-section births and ASD, which found that exposure to general anesthesia may explain the association.
Whatever the cause, health practitioners are seeing the consequences in real time.
"People say rates are higher because of the changes in the diagnostic criteria," said Dr. Roseann Capanna-Hodge, a psychologist in Ridgefield, CT. "And they say it's easier for children to get identified. I say that's not the truth and that I've been doing this for 30 years, and that even 10 years ago, I did not see the level of autism that I do see today."
Sure, we're better at detecting autism, she added, but the detection improvements have largely occurred at the low- to mid- level part of the spectrum. The higher rates of autism are occurring at the more severe end, in her experience.
A Polarizing Theory
Among the more controversial risk factors scientists are exploring is the role environmental toxins may play in the development of autism. Some scientists, doctors and mental health experts suspect that toxins like heavy metals, pesticides, chemicals, or pollution may interrupt the way genes are expressed or the way endocrine systems function, manifesting in symptoms of autism. But others firmly resist such claims, at least until more evidence comes forth. To date, studies have been mixed and many have been more associative than causative.
"Today, scientists are still trying to figure out whether there are other environmental changes that can explain this rise, but studies of this question didn't provide any conclusive answer," said Menashe, who also serves as the scientific director of the National Autism Research Center at BGU.
"It's not everything that makes Charlie. He's just like any other kid."
That inconclusiveness has not dissuaded some doctors from taking the perspective that toxins do play a role. "Autism rates are rising because there is a mismatch between our genes and our environment," said Julia Getzelman, a pediatrician in San Francisco. "The majority of our evolution didn't include the kinds of toxic hits we are experiencing. The planet has changed drastically in just the last 75 years –- it has become more and more polluted with tens of thousands of unregulated chemicals being used by industry that are having effects on our most vulnerable."
She cites BPA, an industrial chemical that has been used since the 1960s to make certain plastics and resins. A large body of research, she says, has shown its impact on human health and the endocrine system. BPA binds to our own hormone receptors, so it may negatively impact the thyroid and brain. A study in 2015 was the first to identify a link between BPA and some children with autism, but the relationship was associative, not causative. Meanwhile, the Food and Drug Administration maintains that BPA is safe at the current levels occurring in food, based on its ongoing review of the available scientific evidence.
Michael Mooney, President of St. Louis-based Delta Genesis, a non-profit organization that treats children struggling with neurodevelopmental delays like autism, suspects a strong role for epigenetics, which refers to changes in how genes are expressed as a result of environmental influences, lifestyle behaviors, age, or disease states.
He believes some children are genetically predisposed to the disorder, and some unknown influence or combination of influences pushes them over the edge, triggering epigenetic changes that result in symptoms of autism.
For Stefania Sterling, it doesn't really matter how or why she had an autistic child. That's only one part of Charlie.
"It's not everything that makes Charlie," she said. "He's just like any other kid. He comes with happy moments. He comes with sad moments. Just like my other three kids."
So-Called “Puppy Mills” Are Not All As Bad As We Think, Pioneering Research Suggests
Candace Croney joined the faculty at Purdue University in 2011, thinking her job would focus on the welfare of livestock and poultry in Indiana. With bachelor's, master's, and doctoral degrees in animal sciences, her work until then had centered on sheep, cattle, and pigs. She'd even had the esteemed animal behaviorist Temple Grandin help shape her master's research project.
Croney's research has become the first of its kind in the world—and it's challenging our understanding of how dog breeding is being done.
Then came an email from a new colleague asking Croney to discuss animal welfare with some of Indiana's commercial dog breeders, the kind who produce large quantities of puppies for sale in pet stores.
"I didn't even know the term commercial breeders," Croney says. "I'd heard the term 'puppy millers.' That's pretty much what I knew."
She went to the first few kennels and braced herself for an upsetting experience. She's a dog lover who has fostered shelter mutts and owned one, and she'd seen the stories: large-scale breeders being called cruel and evil, lawmakers trying to ban the sale of commercially bred puppies, and constant encouragement to rescue a dog instead of paying into a greedy, heartless "puppy mill" industry.
But when she got to the kennels, she was surprised. While she encountered a number of things she didn't like about the infrastructure at the older facilities—a lack of ventilation, a lot of noise, bad smells—most of the dogs themselves were clean. The majority didn't have physical problems. No open sores. No battered bodies. Nothing like what she'd seen online.
But still, the way the dogs acted gave her pause.
"Things were, in many regards, better than I thought they would be," Croney says. "Google told me the dogs would be physically a mess, and they weren't, but behaviorally, things were jumping out at me."
While she did note that some of the breeders had play yards for their pups, a number of the dogs feared new people and things like leashes because they hadn't been exposed to enough of them. Some of the dogs also seemed to lack adequate toys, activities, and games to keep them mentally and physically stimulated.
But she was there strictly as a representative of the university to ask questions and offer feedback, no more or less. A few times, she says, she felt like the breeders wanted her to endorse what they were doing, "and I immediately got my back up about that. I did not want my name used to validate things that I could tell I didn't agree with. It was uncomfortable from that perspective."
After sharing the animal-welfare information her colleague had requested, Croney figured that was that. She never expected to be in a commercial kennel again. But six months later, her phone rang. Some of the people she'd met were involved in legislative lobbying, and they were trying to write welfare standards for Indiana's commercial breeders to follow.
In the continuing battle over what is, and is not, a "puppy mill," they wanted somebody with a strong research background to set a baseline standard, somebody who would actually bring objectivity to the breeder-activist conflict without being on one side or the other.
In other words, they wanted Croney's help to figure out not only appropriate enclosure sizes, but also requirements for socialization and enrichment activities—stimulation she knew the dogs desperately needed.
"I thought, crap, how am I not going to help?" she recalls. "And they said, 'Well how long will that take? A couple of weeks? A month?'"
Dr. Croney with Theo, whom she calls "a beloved family member of our research team."
(Photo credit: Purdue University/Vincent Walter)
Six years later, Croney's research remains ongoing. It has become the first of its kind in the world—and it's challenging our understanding of how dog breeding is being done, and how it could and should be done for years to come.
How We Got Here
Americans have been breeding pet dogs in large-scale kennels since World War II. The federal standard that regulates those kennels is the Animal Welfare Act, which President Johnson signed into law in 1966. Back then, people thought it was OK to treat dogs a lot differently than they do today. The law has been updated, but it still allows a dog the size of a Beagle to be kept in a cage the size of a dishwasher all day, every day because for some dogs, when the law was written, having a cage that size meant an improvement in living conditions.
Countless commercial breeders, who are regularly inspected under the Animal Welfare Act, have long believed that as long as they followed the law, they were doing things right. And they've seen sales for their puppies go up and up over the years. About 38 percent of U.S. households now own one or more dogs, the highest rate since the American Veterinary Medical Association began measuring the statistic in 1982.
Consumers now demand eight million dogs per year, which has reinforced breeders' beliefs that despite what activists shout at protests, the breeders are actually running businesses the public supports. As one Ohio commercial breeder—long decried by activists as a "puppy mill" owner—told The Washington Post in 2016, "This is a customer-driven industry. If we weren't satisfying the customer, we'd starve to death. I've never seen prices like the ones we're seeing now, in my whole career."
That breeder, though, is also among leading industry voices who say they understand that public perception of what's acceptable and what's not in a breeding kennel has changed. Regardless of what the laws are, they say, kennels must change along with the public's wishes if the commercial breeding industry is going to survive. The question is how, exactly, to move from the past to the future, at a time when demands for change have reached a fever pitch.
"The Animal Welfare Act, that was gospel. It meant you were taking care of dogs," says Bob Vetere, former head of the American Pet Products Association and now chairman of the Pet Leadership Council. "That was, what, 40 years ago? Things have evolved. People understand much more since then—and back then, there were maybe 20 million dogs in the country. Now, there's 90 million. It's that dramatic. People love their dogs, and everybody is going to get one."
Vetere became an early supporter of Croney's research, which, unbelievably, became the first ever to focus on what it actually means to run a good commercial breeding kennel. At the start of her research, Croney found that the scientific literature underpinning many existing laws and opinions was not just lacking, but outright nonexistent.
"We kept finding it over and over," she says of the literature gaps, citing common but uninformed beliefs about appropriate kennel size as just one example. "I can't find any research about how much space they're supposed to have. People said, 'Yeah, we had a meeting and a bunch of people made some recommendations.'"
She started filling in the research gaps with her team at Purdue, building relationships with dog breeders until she had more than 100 kennels letting her methodically figure out what was actually working for the dogs.
"The measurable successes in animal welfare over the past 50 years began from a foundation in science."
Creating Standards from Scratch
Other industry players soon took notice. One was Ed Sayres, who had served as CEO of the ASPCA for nearly a decade before turning his attention to lobbying efforts regarding the "puppy mill" issue. He recognized that what Croney was doing for commercial breeding mirrored the early work researchers started a half-century ago in the effort that led to better shelters all across America today.
"The measurable successes in animal welfare over the past 50 years began from a foundation in science," Sayres says. "Whether it was the transition to more humane euthanasia methods or how to manage dog and cat overpopulation, we found success from rigorous examination of facts and emerging science."
Sayres, Vetere, and others began pushing for the industry to support Croney's work, moving the goalposts beyond Indiana to the entire United States.
"If you don't have commercial breeding, you have people importing dogs from overseas with no restrictions, or farming in their backyards to make money," Vetere says. "You need commercial breeders with standards—and that's what Candace is trying to create, those standards."
Croney ended up with a $900,000 grant from three industry organizations: the World Pet Association, Pet Food Institute, and the Pet Industry Joint Advisory Council. With their support, she created a nationwide program called Canine Care Certified, like a Good Housekeeping Seal of Approval for a kennel. The program focuses on outcome-based standards, meaning she looks at what the dogs tell her about how well they are doing through their health and behavior. For the most part, beyond baseline requirements, the program lets a breeder achieve those goals in whatever ways work for the dogs.
The approach is different from many legislative efforts, with laws stating a cage must be made three feet larger to be considered humane. Instead, Croney walks through kennels with breeders and points out, for instance, which puppies in a litter seem to be shy or fearful, and then teaches the breeders how to give those puppies better socialization. She helps the breeders find ways to introduce dogs to strangers and objects like umbrellas that may not be part of regular kennel life, but will need to become familiar when the breeding dog retires and gets adopted into a home as a pet. She helps breeders understand that dogs need mental as well as physical stimulation, whether it comes from playing with balls and toys or running up and down slides.
The breeders can't learn fast enough, Croney says, and she remains stunned at how they constantly ask for more information—an attitude that made her stop using the term "puppy mill" to describe them at all.
"Now, full disclosure: Given that all of these kennels had volunteered, the odds were that we were seeing a skewed population, and that it skewed positive," she says. "But if you read what was in the media at the time, we shouldn't have been able to find any. We're told that all these kennels are terrible. Clearly, it was possible to get a positive outcome."
To Buy or Not to Buy?
Today, she says, she's shocked at how quickly some of the kennels have improved. Facilities that appalled her at first sight now have dogs greeting people with wagging tails.
"Not only would I get a dog from them, but would I put my dog there in that kennel temporarily? Yeah, I would."
"The most horrifying thing I learned was that some of these people weren't doing what I'd like to see, not because they didn't care or only wanted money, but because nobody had ever told them," she says. "As it turned out, they didn't know any different, and no one would help them."
For Americans who want to know whether it's OK to get a commercially bred puppy, Croney says she thinks about her own dogs. When she started working with the breeders, there were plenty of kennels that, she says, she would not have wanted to patronize. But now she's changing her mind about more and more of them.
"I'm just speaking as somebody who loves dogs and wants to make sure I'm not subsidizing anything inhumane or cruel," she says. "Not only would I get a dog from them, but would I put my dog there in that kennel temporarily? Yeah, I would."
She says the most important thing is for consumers to find out how a pup was raised, and how the pup's parents were raised. As with most industries, commercial breeders run the gamut, from barely legal to above and beyond.
Not everyone agrees with Croney's take on the situation, or with her approach to improving commercial breeding kennels. In its publication "Puppy Mills and the Animal Welfare Act," the Humane Society of the United States writes that while Croney's Canine Care Certified program supports "common areas of agreement" with animal-welfare lobbyists, her work has been funded by the pet industry—suggesting that it's impure—and a voluntary program is not enough to incentivize breeders to improve.
New laws, the Humane Society states, must be enacted to impose change: "Many commercial dog breeding operators will not raise their standards voluntarily, and even if they were to agree to do so it is not clear whether there would be any independent mechanism for enforcement or transparency for the public's sake. ... The logical conclusion is that improved standards must be codified."
Croney says that type of attitude has long created resentment between breeders and animal-welfare activists, as opposed to actual kennel improvements. Both sides have a point; for years, there have been examples of bottom-of-the-barrel kennels that changed their ways or shut down only after regulators smacked them with violations, or after lawmakers raised operating standards in ways that required improvements for the kennels to remain legally in business.
At the same time, though, powerful organizations including the Humane Society—which had revenue of more than $165 million in 2018 alone—have routinely pushed for bans on stores that sell commercially bred puppies, and have decried "puppy mills" in marketing and fund-raising literature, without offering financial grants or educational programs to kennels that are willing to improve.
Croney believes that the reflexive demonization of all commercial breeders is a mistake. Change is more effective, she says, when breeders "want to do better, want to learn, want to grow, and you treat them as advocates and allies in doing something good for animal welfare, as opposed to treating them like they're your enemies."
"If you're watching undercover videos about people treating animals in bad ways, I'm telling you, change is happening."
She adds that anyone who says all commercial breeders are "puppy mills" needs to take a look at the kennels she's seen and the changes her work has brought—and is continuing to bring.
"The ones we work with are working really, really hard to improve and open their doors so that if somebody wants to get a dog from them, they can be assured that those dogs were treated with a level of care and compassion that wasn't there five or 10 years ago, but that is there now and will be better in a year and will be much better in five years," she says. "If you're watching undercover videos about people treating animals in bad ways, I'm telling you, change is happening. It is so much better than people realize, and it continues to get even better yet."
[Editor's Note: This essay is in response to our current Big Question, which we posed to experts with different perspectives: "How should DNA tests for intelligence be used, if at all, by parents and educators?"]
Imagine a world in which pregnant women could go to the doctor and obtain a simple inexpensive genetic test of their unborn child that would allow them to predict how tall he or she would eventually be. The test might also tell them the child's risk for high blood pressure or heart disease.
Can we use DNA not to understand, but to predict who is going to be intelligent or extraverted or mentally ill?
Even more remarkable -- and more dangerous -- the test might predict how intelligent the child would be, or how far he or she could be expected to go in school. Or heading further out, it might predict whether he or she will be an alcoholic or a teetotaler, or straight or gay, or… you get the idea. Is this really possible? If it is, would it be a good idea? Answering these questions requires some background in a scientific field called behavior genetics.
Differences in human behavior -- intelligence, personality, mental illness, pretty much everything -- are related to genetic differences among people. Scientists have known this for 150 years, ever since Darwin's half-cousin Francis Galton first applied Shakespeare's phrase, "Nature and Nurture" to the scientific investigation of human differences. We knew about the heritability of behavior before Mendel's laws of genetics had been re-discovered at the end of the last century, and long before the structure of DNA was discovered in the 1950s. How could discoveries about genetics be made before a science of genetics even existed?
The answer is that scientists developed clever research designs that allowed them to make inferences about genetics in the absence of biological knowledge about DNA. The best-known is the twin study: identical twins are essentially clones, sharing 100 percent of their DNA, while fraternal twins are essentially siblings, sharing half. To the extent that identical twins are more similar for some trait than fraternal twins, one can infer that heredity is playing a role. Adoption studies are even more straightforward. Is the personality of an adopted child more like the biological parents she has never seen, or the adoptive parents who raised her?
Twin and adoption studies played an important role in establishing beyond any reasonable doubt that genetic differences play a role in the development of differences in behavior, but they told us very little about how the genetics of behavior actually worked. When the human genome was finally sequenced in the early 2000s, and it became easier and cheaper to obtain actual DNA from large samples of people, scientists anticipated that we would soon find the genes for intelligence, mental illness, and all the other behaviors that were known to be "heritable" in a general way.
But to everyone's amazement, the genes weren't there. It turned out that there are thousands of genes related to any given behavior, so many that they can't be counted, and each one of them has such a tiny effect that it can't be tied to meaningful biological processes. The whole scientific enterprise of understanding the genetics of behavior seemed ready to collapse, until it was rescued -- sort of -- by a new method called polygenic scores, PGS for short. Polygenic scores abandon the old task of finding the genes for complex human behavior, replacing it with black-box prediction: can we use DNA not to understand, but to predict who is going to be intelligent or extraverted or mentally ill?
Prediction from observing parents works better, and is far easier and cheaper, than anything we can do with DNA.
PGS are the shiny new toy of human genetics. From a technological standpoint they are truly amazing, and they are useful for some scientific applications that don't involve making decisions about individual people. We can obtain DNA from thousands of people, estimate the tiny relationships between individual bits of DNA and any outcome we want — height or weight or cardiac disease or IQ — and then add all those tiny effects together into a single bell-shaped score that can predict the outcome of interest. In theory, we could do this from the moment of conception.
Polygenic scores for height already work pretty well. Physicians are debating whether the PGS for heart disease are robust enough to be used in the clinic. For some behavioral traits-- the most data exist for educational attainment -- they work well enough to be scientifically interesting, if not practically useful. For traits like personality or sexual orientation, the prediction is statistically significant but nowhere close to practically meaningful. No one knows how much better any of these predictions are likely to get.
Without a doubt, PGS are an amazing feat of genomic technology, but the task they accomplish is something scientists have been able to do for a long time, and in fact it is something that our grandparents could have done pretty well. PGS are basically a new way to predict a trait in an individual by using the same trait in the individual's parents — a way of observing that the acorn doesn't fall far from the tree.
The children of tall people tend to be tall. Children of excellent athletes are athletic; children of smart people are smart; children of people with heart disease are at risk, themselves. Not every time, of course, but that is how imperfect prediction works: children of tall parents vary in their height like anyone else, but on average they are taller than the rest of us. Prediction from observing parents works better, and is far easier and cheaper, than anything we can do with DNA.
But wait a minute. Prediction from parents isn't strictly genetic. Smart parents not only pass on their genes to their kids, but they also raise them. Smart families are privileged in thousands of ways — they make more money and can send their kids to better schools. The same is true for PGS.
The ability of a genetic score to predict educational attainment depends not only on examining the relationship between certain genes and how far people go in school, but also on every personal and social characteristic that helps or hinders education: wealth, status, discrimination, you name it. The bottom line is that for any kind of prediction of human behavior, separation of genetic from environmental prediction is very difficult; ultimately it isn't possible.
Still, experts are already discussing how to use PGS to make predictions for children, and even for embryos.
This is a reminder that we really have no idea why either parents or PGS predict as well or as poorly as they do. It is easy to imagine that a PGS for educational attainment works because it is summarizing genes that code for efficient neurological development, bigger brains, and swifter problem solving, but we really don't know that. PGS could work because they are associated with being rich, or being motivated, or having light skin. It's the same for predicting from parents. We just don't know.
Still, experts are already discussing how to use PGS to make predictions for children, and even for embryos.
For example, maybe couples could fertilize multiple embryos in vitro, test their DNA, and select the one with the "best" PGS on some trait. This would be a bad idea for a lot of reasons. Such scores aren't effective enough to be very useful to parents, and to the extent they are effective, it is very difficult to know what other traits might be selected for when parents try to prioritize intelligence or attractiveness. People will no doubt try it anyway, and as a matter of reproductive freedom I can't think of any way to stop them. Fortunately, the practice probably won't have any great impact one way or another.
That brings us to the ethics of PGS, particularly in the schools. Imagine that when a child enrolls in a public school, an IQ test is given to her biological parents. Children with low-IQ parents are statistically more likely to have low IQs themselves, so they could be assigned to less demanding classrooms or vocational programs. Hopefully we agree that this would be unethical, but let's think through why.
First of all, it would be unethical because we don't know why the parents have low IQs, or why their IQs predict their children's. The parents could be from a marginalized ethnic group, recognizable by their skin color and passed on genetically to their children, so discriminating based on a parent's IQ would just be a proxy for discriminating based on skin color. Such a system would be no more than a social scientific gloss on an old-fashioned program for perpetuating economic and cognitive privilege via the educational system.
People deserve to be judged on the basis of their own behavior, not a genetic test.
Assigning children to classrooms based on genetic testing would be no different, although it would have the slight ethical advantage of being less effective. The PGS for educational attainment could reflect brain-efficiency, but it could also depend on skin color, or economic advantage, or personality, or literally anything that is related in any way to economic success. Privileging kids with higher genetic scores would be no different than privileging children with smart parents. If schools really believe that a psychological trait like IQ is important for school placement, the sensible thing is to administer the children an actual IQ test – not a genetic test.
IQ testing has its own issues, of course, but at least it involves making decisions about individuals based on their own observable characteristics, rather than on characteristics of their parents or their genome. If decisions must be made, if resources must be apportioned, people deserve to be judged on the basis of their own behavior, the content of their character. Since it can't be denied that people differ in all sorts of relevant ways, this is what it means for all people to be created equal.
[Editor's Note: Read another perspective in the series here.]