My husband insists that his clothes and those of the kids be washed before they are worn, because of the possibility of getting a rash from chemicals used to clean them, or the dyes, or something. His concern with the kids is that if the new clothes made them itchy or gave them a rash, they might not be able to figure out/articulate what is wrong, and so they might be exposed longer (whereas an adult might realize what was going on and take the new socks off). I personally don't care and have never had a reaction, so I wear my clothes new. I don't think a reaction is likely, but I don't mind humoring him. Like somebody else mentioned, I like getting to wear the item when it's perfect, especially as a lot of sweaters don't look quite as nice once they've been washed once.