As published in the NYT today, there may be some positives in unhygienic parctices by children! Nail biting and thumb sucking may have some benefits afterall.
“In a study published Monday in the journal Pediatrics, researchers drew evidence from an ongoing study of New Zealand children to show those whose parents described them as thumb-suckers and nail-biters were less likely to have positive allergic skin tests later in life…..Dr. Hancox pointed out that the study does not show any mechanism to account for the association. “Even if we assume that the protective effect is due to exposure to microbial organisms, we don’t know which organisms are beneficial or how they actually influence immune function in this way.”