Jane had the bad habit of biting her nails. every time she indulged in biting her nails, her mother scolded her sternly. the result was that jane eventually grew out of this bad habit. this is an example of

This is an example of negative reinforcement.

Her mother scolded her every time Jane bit her nails - so Jane learned that every time she bites her nails, she is going to be scolded sternly by her mother. In order to avoid that, she stopped biting her nails, and thus the reinforcement was successful.