There was good reason to feel that science and reason were under attack in 2017: Donald Trump spoke more mistruths than any other president on record (with little impact on his approval ratings), anti-science attitudes were on display at just about every federal health and science agency in government, and Gwyneth Paltrow’s Goop expanded while pushing pseudoscientific bunk on the world.

But at Vox’s science desk, we like to take a glass-half-full approach to life ... and hope that 2018 can be a better year for science literacy and empirical evidence than last year was.

To start the year off right, a housecleaning is in order. Let’s let these eight myths and misconceptions die as we move into 2018. (Check out last year’s list here.)

Myth 1) Voters make decisions based on facts

We have a vision of democracy in which a virtuous public steers the decisions of leaders and those leaders are held accountable to facts. Often, we assume, people make up their minds after a careful weighing of evidence, based on facts, reason, and our experience in the world.

But this assumption is incorrect. Over and over again, experiments in labs — and in the real world — show us that the vision of a virtuous, rational, informed public is a bit of a mirage.

Consider these findings from psychology that Vox has reported on in the past year:

Trump supporters knew he lied during the election, but that didn’t change how they felt about him.

Only about 20 to 40 percent of the public holds stable views on policy. Our views tend to sway depending on who is in charge.

People participating in a psychological experiment rated listening to a political opponent as being almost as pleasant as getting a tooth pulled.

Conservatives will support a liberal policy if they learn Trump supports that same liberal policy.

Instead of facts, we are often guided by our emotions and deeply held biases. Humans are also very adept at ignoring facts so that we can continue to see the world in a way that conforms to our preconceived notions. We respond to emotions: We work to protect and love our in-groups, but fear and avoid out-groups.

And simply stating factual information that contradicts deeply held beliefs is often not enough to combat the spread of misinformation. Frustratingly, research finds that the more knowledgeable we are about politics, the more stubborn we get on politically charged topics. We use our smarts to protect our political groups, not to grapple with uncomfortable truths.

Knowing all this might not change the current situation, where fake news and conspiracy theories easily sweep into people’s newsfeeds and then their minds. But it does make us less naive. We can’t fight misinformation by simply throwing more facts at people, or warning people that information is in dispute (as Facebook tried, and failed, to do). And we have to grapple with the fact that just repeating lies make them more likely to be believed — a lesson Google and Facebook, the de facto chief publishers of news in our connected worlds, ought to learn cold.

And the science does offer some hope. One study reassuringly found that a sense of wonder and curiosity can help people avoid the trap of politically motivated reasoning. And there are ways to get people to realize the hypocrisy of their prejudice-laden arguments. It’s not easy, but it can happen.

Myth 2) Addiction is a moral failure

If you talk to doctors and experts about addiction, they’ll tell you that addiction is a medical condition, not unlike cancer, that needs medical help.

Yet many of us still perceive people addicted to drugs not as victims of a disease, but as wrongdoers and perpetrators of their own illness, deserving of judgment and scorn.

Stigma is everywhere. It’s in policies. It’s in doctors’ offices. It’s in individuals, even those suffering from addiction. And it holds everything back.

Even our lawmakers sometimes argue that addiction is a moral failure. For example, Missouri state Sen. Rob Schaaf, a Republican, once remarked that when people die of overdoses, that “just removes them from the gene pool.” And in Lawrence County, Indiana, lawmakers shut down a needle exchange program earlier this year, citing their “morals” and the Bible.

Needle exchange programs are based on empirical evidence and have been vetted by Johns Hopkins researchers, the World Health Organization, and the Centers for Disease Control and Prevention. They should be one of the least controversial ideas in public health; for decades, studies have repeatedly found that the programs help prevent the spread of diseases, such as HIV and hepatitis C, that can spread through used syringes, while not increasing overall drug use.

This stigma is extremely destructive, particularly since the US is currently overwhelmed by its deadliest drug overdose crisis in history in the opioid epidemic. Experts say the best way to confront the crisis is by dealing with it as a public health issue — and boosting access to treatment (particularly highly effective medications for opioid addiction).

If we want to truly combat addiction — and the opioid crisis — we need to move away from stigmatization. And we need to focus on dedicating resources to the proven solutions we already have.

Myth 3) Opioids are effective for treating chronic back pain

Medicine has historically been pretty terrible at treating chronic lower back pain. Many of the most popular treatments on offer — surgery, steroid injections, and, lately, opioids — have been proven ineffective in the majority of cases, and sometimes are downright harmful.

Consider this randomized controlled trial (soon to be published), which was the first to compare the long-term use of opioids versus non-opioid medications (such as anti-inflammatory drugs and acetaminophen) for low back pain. After a year, the researchers found opioids did not improve patients’ pain or function, and the people on opioids were actually in slightly more pain compared to the non-opioid group (perhaps the result of “opioid-induced hyperalgesia” — heightened pain brought on by these drugs).

Related A comprehensive guide to the new science of treating lower back pain

Yet 20 percent of back pain patients receive long-term opioid prescriptions. And so medical societies and public health agencies are now advising doctors to try less invasive options and even alternative therapies before considering opioids for back pain.

Most recently, in February 2017, the American College of Physicians advised doctors and patients try “non-drug therapies” such as exercise, acupuncture, tai chi, yoga, and even chiropractics, and avoid prescription drugs or surgical options wherever possible. (If the non-drug therapies fail, they recommended non-steroidal anti-inflammatory drugs as a first-line therapy.) In March 2016, the Centers for Disease Control and Prevention also came out with new guidelines urging health care providers to turn to non-drug options and non-opioid painkillers before considering opioids.

Active therapies (exercise programs, yoga, tai chi) seem to really help people work through back pain, and alternative approaches (massage, spinal manipulation) can be effective, too — with the caveat that they’re often no panacea and the effects tend to be short-lived and moderate. But most of the alternatives also carry little or no harm (except to patients’ pocketbooks) — which makes them all the more appealing amid the historic drug crisis.

Myth 4) “Statistically significant” means “strong scientific evidence”

Most casual readers of scientific research know that for results to be declared “statistically significant,” they need to pass a simple test. The answer to this test is called a p-value. And if your p-value is less than .05, bingo, you got yourself a statistically significant result, worthy of publication.

But as researchers have (painfully) realized over the past several years, this threshold does not represent very strong evidence at all. For one: It can be gamed. Researchers can run a whole array of tests and only report the result that, by chance, yielded a significant result (this is sometimes called p-hacking).

But it’s also because researchers have placed undue confidence in their p-values.

A p<.05 does not mean there’s less than a 5 percent chance your experimental results are due to random chance. It does not mean there’s only a 5 percent chance you’ve landed on a false positive. Nope. Not at all. The false-positive rate for experiments that hit the p=.05 threshold can be much, much higher than 5 percent. This is a fact that many social scientists are reckoning with in their ongoing “replication crisis.”

(Read a fuller explanation of p-values, and the debate about how they are used and interpreted, here.)

Myth 5) Placebos are useless

You may have heard someone disparage anti-depression medication by saying it’s mostly a placebo effect, or that alternative medical treatments like acupuncture or Reiki are duping people to spend money on placebos. Placebos get a bad rap. Yet researchers are learning that placebos — drugs, therapies, or surgeries that ought to do nothing — are weirder and more potentially useful than we’d expect.

In medicine, placebo pills are typically used as a tool to test the effectiveness of real drugs. In a double-blind, placebo-controlled clinical trial, which researchers consider the gold standard for testing a drug’s effects, patients (and the doctors running the trial) don’t know who’s taking the real drug and who’s taking the placebo.

In recent years, Harvard researcher Ted Kaptchuk has been running drug trials, but doesn’t give patients any active drugs at all. Instead, he’s found that giving patients open-label placebos — sugar pills that the doctors admit are sugar pills — improved symptoms of certain chronic conditions that are among the hardest for doctors to treat, including irritable bowel syndrome and lower back pain.

But that’s not all. The new science of placebo is bringing new understanding to a lot of other areas of medicine and health care. For instance:

Pain-killing drugs like morphine provide more relief when patients see doctors administer the drug.

The placebo effect is stronger when treatment is administered by a warm, friendly practitioner.

When study participants see another patient get relief from a placebo treatment, they have a greater placebo response.

get relief from a placebo treatment, they have a greater placebo response. That placebos actually lead to the release of natural opioids in the brain.

Placebo can only help symptoms that can be modulated by the mind. You can’t, for example, condition the cancer-killing effects of chemotherapy. Our bodies don’t produce cancer-killing chemicals. But there’s increasing evidence that doctors can harness to power of the placebo effect to help people ignore painful systems.

So saying “it’s just a placebo” when talking about alternative treatments may be downplaying their potential usefulness.

Myth 6) Exercise is the best solution for obesity

We’ve been conditioned to think of exercise as perhaps the most important component of any weight loss effort. You know the drill: Join the gym on January 1 if you want to reach your New Year’s weight loss goal.

But the evidence has been accumulating for years that exercise, while great for health, isn’t actually all that important for weight loss.

To learn more about why, I (Julia) read through more than 60 studies (including high-quality, systematic reviews of all the best available research) on exercise and weight loss this year. I learned that the extra calories you burn only account for a small part of your total energy expenditure, and that cutting your food intake is a much more efficient way to lose weight. Obesity doctors have even been calling for a rebranding of how we think about exercise.

To be clear: Exercise has huge benefits — it reduces the risk of chronic conditions like Type 2 diabetes and heart disease, it strengthens your bones and muscles, and it even helps with weight management — it just isn’t the most effective way to slim down.

But in 2018, we need to stop treating a lack of exercise and diet as equally responsible for the obesity problem in this country. Public health obesity policies should prioritize fighting the overconsumption of low-quality food and improving the food environment. And we should take the most cost-effective treatment we have for obesity — bariatric surgery — more seriously.

Myth 7) Homeopathy works

Homeopathy is one of the most enduring forms of snake oil available to consumers; it has been duping people since 1814. The main idea behind homeopathy is that an animal or plant extract that causes symptoms similar to the ones a person is suffering from can cure the symptoms. So homeopathic remedies on the market are just extremely diluted versions of plant or animal extracts believed to bring relief to symptoms.

The scientific community is monolithically stacked against homeopathy. There have been many studies, books, and investigations demonstrating that this type of therapy is bogus. There's so much evidence on homeopathy's failure to help people, in fact, that some researchers have argued it’s time to stop investing government research funding into this alternative therapy in favor of putting it into treatments that might actually help people.

That’s why in December, the Food and Drug Administration proposed a new rule to more strictly regulate homeopathic products, holding them to the same standards as any other drug product.

This follows last year’s policy statement from the Federal Trade Commission, which explained that the agency will now ask that the makers of homeopathic drugs present reliable scientific evidence for their health claims if they want to sell them to consumers on the US market.

The FDA and FTC crackdowns are definitely steps in the right direction of raising awareness that homeopathy is mostly ... rubbish. And rubbish with concerning reach. As the FDA said in a statement, “Over the last decade, the homeopathic drug market has grown exponentially, resulting in a nearly $3 billion industry.” During the same period, the FDA has documented an increase in reported safety concerns about homeopathic products, such as the homeopathic teething tablets and gels that contained belladonna, a toxic substance that can cause seizures or deaths in infants and children.

But the moves by federal regulators don’t mean homeopathic products will suddenly disappear from the market. The FDA plans to focus on the highest-risk products, such as those marketed for infants or for people with serious illnesses like cancer. So low-risk products would remain on store shelves. And the FTC only has the right to crack down on misleading marketing claims, and if the makers of homeopathic remedies clearly state that their products are based on no science, they can still sell them.

So for now, it’ll still be buyer beware.

Myth 8) We need a “debate” about climate change

There’s been a concerted push over the past few decades from climate skeptics to frame climate change as a political, or cultural, dispute rather than a scientific matter. Some skeptics have even described the scientific consensus that humans are driving the current planetary warming trend as a “secular religion.”

This year, Environmental Protection Agency Administrator Scott Pruitt, who doesn’t believe carbon dioxide warms the planet, broached the idea of holding a debate to critique climate science.

Pruitt, a lawyer by training, suggested that the science around climate change needs to face a “red team/blue team” exercise modeled on how the military tests its plans against an in-house opponent, in this case presented as a televised event.

But as Vox’s David Roberts explained, the idea is at best deeply flawed, and at worst a charade to obfuscate the robust agreement that scientists have on humanity’s role in the global climate.

For starters, climate researchers, like all scientists, already face an adversarial process known as peer review. Challenging, scrutinizing, and dissecting new findings is the foundation of research, and while no human endeavor is perfect, there’s also no evidence that the peer review process has failed climate science.

In fact, scientists like University of California Berkeley’s Richard Muller, a one-time climate skeptic who launched a review of climate change science funded by the Charles G. Koch Charitable Foundation, concluded that “global warming was real and that the prior estimates of the rate of warming were correct,” adding that “[h]umans are almost entirely the cause.”

On the other hand, Pruitt and other members of the Trump administration like Energy Secretary Rick Perry have already made up their minds that humanity doesn’t play the dominant role in the rising temperatures we’ve witnessed, so many scientists don’t see this as a good-faith endeavor.

When discrepancies do inevitably arise in our understanding of the global climate, they are resolved with more evidence and experiments, not with people shouting across lecterns. Ultimately, a red-team exercise is a great tool for testing decisions, but a mediocre method for vetting the truth.