To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This chapter uses the phrase nail biting rather than onychophagia because nail biting is more easily understood. Although most nail biters bite only their fingernails, some people bite their toenails as well or overclip their toenails. Occasionally, people may bite their nails as part of a behavioral disorder occasioned by intense pain. Nail biting can be reliably and simply measured by using calipers. For older teenagers and adults, the data from Malone and Massler's study indicate that fewer girls and women than boys and men bite their nails. Studies of obsessive-compulsive spectrum disorders have often revealed quite high levels of nail biting, among other habits. Only one trial of pharmacological agents has been described, in which clomipramine and desimipramine were compared in a double-blind, randomized study. A number of interventions have been proposed, but none has shown clear superiority in adequately designed trials.