Science Daily reveals the hidden health benefits of sucking your thumb and biting your nails:
The researchers [of New Zealand’s Dunedin School of Medicine, assisted by professor Malcolm Sears of McMaster University’s Michael G. DeGroote School of Medicine] were testing the idea that the common childhood habits of thumb-sucking and nail-biting would increase microbial exposures, affecting the immune system and reducing the development of allergic reactions also known as atopic sensitization.
The habits of thumb-sucking and nail-biting were measured in a longitudinal birth cohort of more than 1,000 New Zealand children at ages 5, 7, 9 and 11; and atopic sensitization was measured by skin-prick testing at 13 and 32 years old.
The researchers found 31 per cent of children were frequent thumb suckers or nail biters.
Among all children at 13 years old, 45% showed atopic sensitization, but among those with one oral habit, only 40% had allergies. Among those with both habits, only 31% had allergies.
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In other words, it might not be clean, but that’s what keeps your immune system in top shape.