Thanks to hygiene, antibiotics and too little outdoor play, children don’t get exposed to microbes as they once did. This may lead them to develop immune systems that overreact to substances that aren’t actually threatening—causing allergies. In the same way, by shielding children from every possible risk, we may lead them to react with exaggerated fear to situations that aren’t risky at all and isolate them from the adult skills that they will one day have to master [emphasis added].