Tall people make more money as adults. There is lots of great research about this topic, but the most interesting, to me, is that on average, tall people contribute more to a team than shorter people in a business environment. Probably this is because tall people have more self-confidence because they get treated better because they are tall: geometrically multiplying advantages, or a sentence as an homage to Escher.

I was reading about how tall different flowers grow (yes, that’s my garden right now. I’m so happy,) and I kept finding links at the bottom of articles that offer to tell me how tall my kids will be. Finally I clicked. I want to tell my kids that they determine their own fate, because teaching kids they are the locus of control is essential to a happy life. But in secret I think a lot depends on height and I want to know.

Like IQ. I wouldn’t want to tell my kids’ their IQ, but I had it tested, just so I could relax about how smart they are. So much of parenting is not measurable, so I get as many measurements as I can to assure me my kids are okay.

Not that I know what “okay” really means. But I do know what assurance means. It means being able to breath without a tight stomach and a locked jaw.

School is full of measurements, which makes it enticing to anyone who wants assurance that they are doing a good job. When parents give up raising their own kids for all the hours of the school day, they get something in return that tells them it’s a good idea. Measurements are school’s secret weapon because measurements reassure parents’ weak spot.

Parents can never point to numbers to show they were a good parent but schools are all about numbers and they inundate parents with numbers that are essentially irreproachable since parents have no numbers to counter with. And then, boom: parents have numbers to show they are doing a good job (and they have a bumper sticker that says their kid is an honors student).

An illustration of the dangers of an education-by-numbers mentality is the new findings about grit. Angela Duckworth’s book, Grit, is a New York Times bestseller. People love reading it because Duckworth assures us we don’t have to be the victim of meager talent or lousy genes.

But the book also reveals to us how to help our kids to be more successful as adults. So of course schools are getting involved. Daniel Engber (who  comes up with really interesting topics on Slate that are so fun to read) reports that California public schools are creating a curricula for grit and a way to measure whether teachers have been successful teaching it.

But Duckworth responded by saying grit is not a thing you can measure, because so much of it is about failure. How do you measure if a failure is good or bad? You just keep going.

So what I realized is that we have widespread agreement that we want kids to learn soft skills; positive outlook, grit, diligence, all these things that even university research teams struggle to measure. Which means there is no point trying to teach them in school because school is structured to evaluate everything with a clear means to measurement. The things that do matter to schools (things that can be measured, like height and IQ) do not depend on the efforts of school.

If only schools could make kids taller. Now that would be a reason to send your kid there.