Final answer:
The statement that behavior modification uses learning principles to alter behavior is true as it employs operant conditioning techniques to reinforce desirable behaviors and reduce unwanted ones.
Step-by-step explanation:
Behavior modification indeed uses the principles of operant conditioning to change one's behavior by replacing undesirable behaviors with more socially acceptable ones. So the statement 'When the principles of learning are used to alter undesirable behavior, it is called behavior modification' is true. This process involves reinforcing desired behaviors and decreasing misbehaviors through various reinforcement schedules and types of reinforcement such as positive reinforcement, negative reinforcement, positive punishment, and negative punishment. For children, behavior modification might look like a sticker chart where they earn tokens for good behaviors, demonstrating how operant conditioning works.