This article I ran across on Vox makes me very happy because it reflects something I’ve been teaching students in my classes for years: that being too clean can make you less healthy. This is especially true for children. The article discusses what is known as the hygiene hypothesis, which proposes that exposure to allergens, viruses, bacteria, etc. – in other words, a less than fully sanitized environment – strengthens children’s immune systems by allowing them to develop defenses from a young age (although I hasten to note, as the article does, that this does not mean children should not be vaccinated. In fact, vaccination operates on the same principle: that exposure to a small amount of inert virus primes the immune system to respond when that virus is encountered in the wild. So this is not an excuse to avoid vaccination in favor of deliberately infecting your kid with a disease like measles). Research is starting to show that children who are kept in environments that are too clean are more likely to develop autoimmune diseases such as asthma. I have long railed against the use of products like antibacterial soaps and household cleaning products, hand sanitizers, and antibacterial wipes partly for this reason. I jokingly recommend to my students that if they ever have children, the kids should be rolled about in a dirt pile every day – but I’m not really joking. Here’s one good takeaway from the article: “In the wealthy world, adults who clean their houses with antibacterial sprays have higher asthma rates, and people who are more often exposed to triclosan (the active ingredient in antibacterial soap) have higher rates of allergies and hay fever. Kids who grow up on farms or have pets, meanwhile, have lower rates of allergies and asthma.” Read the entire article to learn more about how our obsession with cleanliness may be affecting our health.