• Popular platitudes can squash your critical thinking, argues moral psychologist Jonathan Haidt. Always trust your feelings? The world is a battle between good and evil? These popular pieces of conventional wisdom are merely myths—ones that can set us up for failure.
• “When we protect children from unpleasantness, from conflicts, from insults, from teasing, from exclusion, we’re preventing their social psychology, we’re preventing their social abilities, we’re preventing their strength from developing,” says Haidt.
• He highlights three great untruths and explains the psychological principles that debunk them. Unlearning a few token ideas can make us more resilient and help us grow, rather than break, in the face of adversity.

JONATHAN HAIDT: So my first book, 'The Happiness Hypothesis', was a collection of ten insights from sages around the world that were psychological truths, and one of them is: What doesn't kill you makes you stronger. That gets at the idea, the psychological principle, of anti-fragility. It's a wonderful term. It's actually a clunky, ugly term, but it was made up by Nassim Taleb because we don't have a word for this in the English language, which is that there's some systems that get stronger if they get pushed around, knocked around.

So a wine glass is fragile; if you knock it over it breaks; nothing good happens. A plastic cup is resilient; if a kid throws it off the table it doesn't break, but nothing good happens.

But there are some things that have to get thrown off the table. There are some systems that have to get pushed around, and Taleb wrote this book 'Antifragile' or antifragility because things like the banking system had to be tested or it gets fragile and collapses. Bones have to be tested, used, or they get weak; if you were to fly to Mars your bones would get weak. The immune system, if you protect kids from bacteria, if you keep them in a sterile environment you're damaging their immune system. The immune system has to face challenges in order to learn.

It turns out kids are anti-fragile and when we protect children from unpleasantness, from conflicts, from insults, from teasing, from exclusion, we're preventing their social psychology, we're preventing their social abilities, we're preventing their strength from developing. The subtitle of our book is 'How Good Intentions and Bad Ideas are Setting Up a Generation for a Failure'—by over-protecting our children we are setting them up to be weak, to be more easily damaged, to be more easily discouraged.

The next untruth is "Always trust your feelings". It may sound wise, it may sound romantic, but wise people around the world have noticed that we don't react to the world as it actually is, we react to the constructions, the perceptions. Epictetus said, "It is not things themselves that disturb us, but our interpretations of things." This is the basis of cognitive behavioral therapy.

Aaron Beck, a psychiatrist in the 1960s, noticed that depressed and anxious people have a way of constructing these beliefs that, "I'm bad, the future is bad, the world is a bad place," and they're mutually reinforcing. And this is the way the world feels to them, and if you can improve their thinking and break up those beliefs, they're released from the depression. What we've begun seeing on campus is that students are encouraged to follow their feelings; if they feel offended by something then they have been attacked. They're supposed to not question those feelings. But part of wisdom is the ability to say, "Now, wait a second, are there other ways to look at this?"

These are crucial skills for critical thinking, these are crucial skills for mental health, and we need to be teaching young people at all stages to question their first interpretations, look for evidence, and improve the way they interpret the world.

The third great untruth, my favorite, the worst and most dangerous and darkest of all is that life is a battle between good people and evil people. If you think about it for a moment, who are we? What is our species? We evolved in small-scale societies that were locked in struggle with other small-scale societies. Human nature is really, really finely tailored for intergroup conflict, for tribal warfare. This is the way our ancestors lived for a long time. Now that we've transcended it we're so desperate for it we've invented team sports, fraternities. We love these sorts of competitions. Our brains are made for it.

Now, it can be fun or it can get dark and it can lead to racism, all kinds of forms of bigotry. If we're creating multiethnic environments on campuses and in most of our organizations we're struggling to increase diversity, what you should obviously be doing is turning down the tribal sentiments, is emphasizing what we have in common. But on some college campuses and in some high schools we see forms of education, forms of training that teach students to make more and more distinctions, to see more and more binary dimensions between people where the people who are high are bad, the people who are low are good. The more we encourage people to see the people around them as good versus evil, the harder it's going to be to create an inclusive, diverse environment.

The bottom line is that there are some very basic important psychological principles. If we're going to raise kids and educate them and bring them through schools and universities, we should get our institutions in line with these principles. They are: Children are anti-fragile, we are all prone to motivated reasoning and the confirmation bias, and we're all prone to tribalism and black and white thinking. We need to be educating kids so that they do less of this stuff. If we want to raise a generation of kids who can deal with diversity of all kinds, who can go out into a world that's physically actually quite safe and yet full of offensive content, we need to get our educational practices in line with these three psychological principles, not with these three great untruths.