As of early June, Minnesota’s measles outbreak has led to more confirmed cases than in all of the United States in 2016.

Minneapolis’s Somali population, in which vaccination rates have sharply decreased throughout the last decade, has seen the majority of the measles cases. In 2014, their vaccination rate was just 42 percent, significantly less than the 95 percent needed to ensure herd immunity.

Part of the reason for that decrease, experts suggest, is the lectures Andrew Wakefield gave to Minneapolis’s Somali community in 2010 and 2011 about the dangers of vaccination.

You may not be familiar with Wakefield’s name, but you’re likely familiar with his most impactful work: linking vaccines and autism. For vaccine skeptics, that work makes him a hero. For vaccine proponents, that makes him a villain.

This article is not another contribution to the larger debate nor is it a judgment of people on either side. Yelling at each other on the Internet is not going to solve the “problem” of vaccines, whether you view the problem as an increasingly unvaccinated population or an increasingly vaccinated one.

Instead, this article focuses on how a single scientific study had such an outsized impact on how the world understands vaccines and autism, and draws out five research lessons all parents can learn from that study.

The link between vaccines and autism

In February 1998 the British medical journal, The Lancet, published Wakefield’s article, “Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.” You wouldn’t expect a paper with that title to generate decades of impassioned fighting over vaccine policy. You probably wouldn’t even expect that of its main finding: that children’s bowel disorders, which might be causing autism, were “generally associated in time with environmental triggers.”

However, if you’d listened to the press conference about that paper, you would have heard Wakefield asserting his belief that the measles, mumps, and rubella (MMR) vaccine was causing autism.

Retraction and disbarment

Even without the fraudulent behavior that led to the paper’s eventual retraction, Wakefield’s work would not have been considered very strong science. First, the study enrolled 12 children. That is an impossibly small size from which to draw any conclusions. The study mostly relied on parents’ narration of events, which is not generally considered strong evidence.

In an editorial that also ran in that February 1998 issue of The Lancet, Robert Chen and Frank DeStefano critiqued Wakefield’s reasoning. They pointed to the millions of vaccinated children around the world who had not experienced gastrointestinal problems. They raised concerns with Wakefield’s data collection, which relied heavily on parents’ memories of events. They warned that correlation of an autism diagnosis with the timing of the MMR vaccine did not mean that one caused the other.

The last paragraph of Chen and DeStefano’s critique is eerily prescient. They feared that without a careful system of rigorous measurement, the vaccine-safety fears stoked by papers like Wakefield’s “may snowball into societal tragedies when the media and the public confuse association with causality and shun immunisation.”

Chen and DeStefano’s concerns were echoed by other researchers and physicians at the time Wakefield’s article was published. Even greater concerns emerged once The Lancet’s editorial staff began investigating ethical claims about Wakefield’s research. By 2010, when Wakefield was giving those lectures targeted at the Somali population of Minneapolis, his article was being retracted and he was being banned from practicing medicine in the U.K.

The Lancet’s editorial staff retracted the article for two main reasons. First, Wakefield and co-authors claimed that the children who participated in the study were “consecutively referred,” meaning that they were chosen as they came and that no eligible participants were selected. That turned out not to be true. Second, Wakefield and co-authors claimed that they had received permission from local ethics boards to conduct the study when they had not.

After the retraction, other investigators found even more serious issues, such as Wakefield’s undisclosed role in a lawsuit against MMR vaccine manufacturers and his falsification of data in each of the 12 cases included in his study.

The aftermath

Wakefield’s disbarment doesn’t appear to have slowed him down. In 2016, he released “Vaxxed: From Coverup to Catastrophe.” The promotional website describes him as “an academic gastroenterologist” before listing his degrees, accolades, and publications.

Despite that description, Andrew Wakefield is not an academic gastroenterologist. He is a disbarred gastroenterologist, disallowed from practicing medicine in both his home country and unlicensed to practice medicine in the United States. He is not employed by an academic medical center. Those details don’t appear until six paragraphs later, so only the most thorough readers are likely to see that information.

In the documentary (and basically to whatever journalist will interview him), Wakefield defends his research and his integrity, noting that he never said that he’d proven a link between the MMR vaccine and autism. But, as Susan Dominus puts it in the New York Times, “his concerns, not his caveats, ricocheted around the world.”

So now here we are in June 201 with a measles outbreak in Minnesota. In an interview for The Washington Post, Wakefield claimed that the Somali community of Minneapolis “had decided themselves that they were particularly concerned” about vaccines. “I was responding to that,” he states. In its coverage of the outbreak, Vox’s Julia Belluz explains what Wakefield imagines himself to be doing: “he’s just giving concerned parents information they want.”

Maybe concerned parents shouldn’t always get what they want.

Five research traps to avoid

You don’t have to look hard for “evidence” that vaccines cause autism, because Wakefield will pop up right at the top of your search results. If you want to build a case that vaccines are dangerous, you can get what you want.

Your child isn’t likely to suffer from this choice, at least not directly. The reason that Minneapolis’s measles cases now outnumber the entire U.S.’s measles cases from 2016 is that, overall, the rate of measles is incredibly low. Even if you choose not to vaccinate, your child isn’t likely to contract any of the diseases that those vaccinations have been designed to ward off, because many other parents will be picking up the slack in establishing herd immunity.

What suffers is science and reason. In a world where the accusations of “fake news” and “alternative facts” are feverishly lobbed at those who disagree with us, it’s more important than ever for parents to model good scientific literacy and critical thinking. It is our obligation as parents to educate ourselves, not about a specific issue like vaccines, but about how to do high-quality research. That education will help us make sense of the seemingly contradictory results in our Google searches.

Trap #1: Googling a yes or no question

Wakefield’s Lancet paper appears to have been built on a yes or no question he already “knew” the answer to. He looked for evidence that a vaccine caused a bowel issue that caused autism, and guess what? He “found” it.

The same basic principle applies to your own research. If you’re asking a yes or no question, you probably already have an answer in mind. If you Google that yes or no question, you will find whichever answer you’re looking for, because it’s incredibly difficult to consider contradictory evidence if you’ve already answered your question.

Of course, it’s impossible to be completely open-minded about the question you’re researching, especially if you’re researching about your own child’s illness. But you can open up your research question by phrasing it in terms of “how” or “why.”

Trap #2: Mistaking correlation for causation

Wakefield’s subjects may very well have had diagnosable autism and diagnosable bowel disorders. They may also have had MMR vaccines near the timing of those other symptoms.

Even if this was the case, the correlation of those conditions is not proof of causation.

Humans are really powerful storytellers. It’s well-documented that we see patterns even when none exist. When we read about medical tragedies online, it’s really easy to connect the dots and decide what caused it, but there are countless other details missing that could help complete the picture.

When conducting your own research, don’t settle for the first cause you find. Or better yet, focus less on what may have caused a medical problem (you don’t have the lab equipment to make that determination, anyway) and instead focus on what to do about symptoms.

Trap #3: Focusing on newsworthy numbers

Humans may be good storytellers, but we are lousy unaided statisticians. When we see an one-in-a-million chance, we tend to see ourselves in the “one” rather than in the “one million.” Or we see a scary sounding conclusion and forget to look at the sample size.

Even if Wakefield’s sample wasn’t compromised, even if his research methods were pure, he only studied 12 children. That’s an incredibly small number to base any conclusion on, especially given the millions of children who have received vaccinations without developing either bowel problems or autism.

When you see stats reported in the news, pause and consider them in context.

Trap #4: Not identifying “they”

In her profile of Wakefield, Susan Dominus mentions his use of a powerful rhetorical tool: “He said he believes that ‘they’ – public-health officials, pharmaceutical companies – pay bloggers to plant vicious comments about him on the Web.”

Even as the medical community was rejecting him, Wakefield’s work continued to gain popularity. Perhaps that’s because of the very scary “they.” Invoking a mysterious other, with potentially impure motives, is a sure way to pull people over to your side. “They” don’t want people to see the research. “They” have money to gain from the existence of vaccines. “They” gain from making vaccine federal policy.

Now imagine that you are a parent to a child with an autism diagnosis. You’re probably also really angry with some amorphous “they.” “They” told you vaccines were safe. “They” didn’t tell you about Wakefield’s work. “They” didn’t catch the warning signs early enough. It’s easy to put your “they” and Wakefield’s “they” together.

In your own research, if you’re seeing frequent references to whatever “they” don’t want you to know, be skeptical. Define “they.” Ask yourself what “they” really have to gain from this supposed deception.

Trap #5: Failing to ask why you’re researching in the first place

Wakefield has defended the conflict-of-interest allegation against him, arguing that none of the money he received from law firms arguing against MMR vaccine manufacturers went to funding the 1998 Lancet paper. Even if that was true, he cannot be an impartial observer of the evidence because his erstwhile employers had something to gain if he concluded in their favor.

Parents who conduct research without asking themselves why they’re doing it may face similar conflicts of interest. It’s hard to be honest with yourself, but asking hard questions about your own research motives can help you avoid most common research traps. Has your child just received a scary diagnosis and you’re looking for comfort? Are you looking for someone to blame? Are you looking to find evidence to win a fight with your spouse or mother-in-law? Those circumstances don’t mean you will do bad research, but they can interfere with your interpretation. Making your own biases clear can help you steer clear of sources that cater to those biases.