Habits can be acquired by conscious repetition and desire to achieve proficiency in an activity.
Many habits are acquired, often without awareness, from influences in the environment. A child, for example, having heard others constantly use meaningless phrases, such as “ermm..as in,” may begin to use them himself to such an extent that the use becomes habitual. Some habits develop in response to a person's unconscious needs.
Thumb-sucking and nail-biting, for example, are usually attempts to relieve tensions of which the individual is not aware. Such habits ordinarily disappear when the tensions causing them are discovered and eliminated.
