Elton's mother has been nagging that he should practice at the piano for the upcoming competition. Elton eventually complies to stop her nagging. This example illustrates .

Negative reinforcement

Explanation:

Negative reinforcement can be defined as the acts or behaviour carried out by person in order to encourage someone to do what he /she said.

Negative reinforcement are often use to encourage or motivate someone and as well change the person behaviour. It also strengthened a person behaviour by removing negative result.

This example "Elton's mother has been nagging that he should practice at the piano for the upcoming competition. Elton eventually complies to stop her nagging" simply illustrates NEGATIVE REINFORCEMENT because Elton's mother was nagging in order to encourage Elton's to practice the piano for the upcoming competition and as well change is behaviour in which Elton finally complies to do what she said due to her nagging.