Thumb sucking, nail biting may combat allergies
Does your child suck her thumb or bite her nails? A long-term study suggests these “bad” habits might actually have a plus side: lasting protection from common allergies. Researchers followed a group of more than 1,000 children in New Zealand from birth through age 32. They asked the parents to report their children’s thumb-sucking and nail-biting habits at ages 5, 7, 9 and 11. Then they tested the children for allergic reactions using a skin-prick test at age 13, and again in adulthood at age 32.