College campuses were once safe spaces for the exchange of ideas. These days, though, both professors and students often feel as if they’re walking on eggshells. We talk with social psychologist Jonathan Haidt to explain why we’re setting students up to fail when we overprotect them during these formative years. He’s a co-author of “The Coddling of the American Mind: How Good Intentions and Bad Ideas are Setting Up a Generation for Failure” (Penguin Press).