Studies are often used to prove stuff. But sometimes they are wrong. Here is an example how the poor night light got a bad name by a botched study.

In 1999 a study was released finding that children who have night lights in their room at the age of 2 or younger often wind up having problems with nearsightedness later in life. There was pandemonium. Parents yanked night lights from the outlets and stomped on them like a wine glass at a jewish wedding. People gathered in the town square and burned night lights.

But there was a major problem with the study: it didn’t take into account parents who were nearsighted. Being nearsighted is hereditary. Parents who were nearsighted had a hard time seeing in their baby’s room and put night lights in there. Night lights, it turns out, was the effect not the cause.

Two year later another study was conducted, with this in mind, and showed there was no evidence of night lights causing vision problems. Parents everywhere apologized to the night light industry and returned the low wattage lights to their children’s bedrooms.

There’s a new study out that says teacher’s who use a lot of hand gestures tend to have students with better grades. But maybe it’s just that Italians are better teachers, and they just like to talk with their hands. Or maybe, they’re not really doing hand gestures but swatting at flies, and the students make sure they do better at the tests so they don’t have to repeat the class with all the damn bugs in it.

The lesson, always be skeptical. And stop blaming night lights for what your own crappy genetics did to your kid.