Why do babies seem to find the act of sucking their thumb comforting?

BRY2K

Infants are hard-wired to need and enjoy sucking as a separate experience from feeding. In some infants this need is more pronounced than in others. Infants tend to exhibit the sucking behavior most when they are tired, bored, or in need of comfort. Some babies who do not suck their thumbs can be comforted, stimulated, or put to sleep through pacifier use. This is often more acceptable to parents since they can control the use of pacifiers. Children who suck their thumbs are able to begin at an early age to meet their own need for sucking. These children fall asleep more easily, are able to put themselves back to sleep at night more easily, and sleep through the night much earlier than infants who do not suck their thumbs. http://www.drgreene.org/body.cfm?id=21&action=detail&ref=29 Jan 21 08, 10:04 PM