The concept of general deterrence assumes that if a man is convicted of murder and sentenced to life in prison, this act will serve as an example for other people.
Explanation:
There is a psychological trait that is common to almost all human beings and that is the fear of getting punished. This specific trait ceases human beings from performing activities that can culminate in their incapacitation.
Because they are aware of the horrendousity of the punishment that their act would attract. This fear of the people is psychologically termed as general deterrence.