Children's Thumb-Sucking and Nail-Biting Habits May Have Health Benefit, Study Says

September 10, 2016

Unlocking Word Meanings

Read the following words/expressions found in today’s article. 

1. habit / ˈhæb ɪt / (n.) – something that a person does regularly
Example: She has a habit of saying “um” before she speaks. 

2. hygiene / ˈhaɪ dʒin / (n.) – the practice of keeping something clean
Example: One practice related to good oral hygiene is brushing one’s teeth daily.

3. exposure / ɪkˈspoʊ ʒər / (n.) – the state of being open to something
Example: She got a sunburn because of her exposure to the midday sun.

4. risk / rɪsk / (n.) – harmful chance
Example: Obese people have a higher risk of developing heart disease.

5. evaluate / ɪˈvæl yuˌeɪt / (v.) – to study something carefully
Example: The doctor evaluated the patient’s laboratory results.


Read the text below.
Children who suck their thumbs and bite their nails are less likely to develop allergies, study says.

Researchers from University of Otago [oh-TAH-go] in New Zealand and McMaster University and St. Joseph’s Healthcare in Canada have discovered a link between these common childhood habits and the development of certain allergies.

The researchers wanted to test the hygiene hypothesis – the theory that a certain level of exposure to various microbes during early childhood helps reduce the risk of developing allergies. Thumb-sucking and nail-biting are common childhood habits that expose children to germs in their immediate environment.

The researchers evaluated data collected from 1,037 people born in Dunedin [duhn-EE-din], New Zealand. They interviewed parents about their children’s thumb-sucking and nail-biting habits. Researchers found that children between five and eleven years old who sucked their thumbs and bit their nails were 33% less likely to develop common allergies from pollen, dust mites, and cats. Furthermore, by the time they reached the age of 32, they were 39% less likely to react to the same allergic substances.

Due to the limitations in the study’s respondents, the study is not considered strong evidence that thumb-sucking and nail-biting have a direct relation to children’s reactions to common allergens. The subjects of the study are all from the same city, and environmental factors and allergy prevalence are different for every place.

Thumb-sucking and nail-biting are common habits of children. Most children discontinue these habits as they grow older. However, persistence of these habits until adulthood can cause serious health problems and social embarrassment.

Viewpoint Discussion

Enjoy a discussion with your tutor.  

Discussion A

·         Aside from serious health problems and social embarrassment, what are the other effects of thumb-sucking and nail-biting in adulthood? Discuss.
·         Do you agree that early exposure to bacteria is beneficial? Why or why not?

Discussion B

·         What is the importance of knowing the health implications of thumb-sucking and nail-biting?
·         What do you think are effective ways to break bad habits, especially among children?

September 10, 2016