It would be impossible for a reasonable person to watch the eight-minute video and come away thinking Mr. Pinker’s point is to praise the alt-right rather than to make a psychological argument about political correctness, alt-right recruitment and how to better fight that movement’s bigoted ideas

Now, maybe you disagree with certain parts of this argument — I do, in that I think Mr. Pinker overstates the intensity of campus political correctness — but it’s hard to have that debate in the first place when such a wildly skewed version of Mr. Pinker’s point is spreading like wildfire on the internet.

Steven Pinker will be O.K. A fleeting Twitter blowup isn’t going to bruise his long and successful career as a public intellectual. But this is happening more and more — and in many cases to people who don’t have the standing and reputation he does.