Four different types of human beings

Reading Swami Vivekananda. Found this very interesting. I didn’t find the original Sanskrit shloka from which he has taken it. He says there are four fundamental types of a person.

1) A God-like person, who can sacrifice anything for the good of others. They are the highest of all. He says if there are 100 like these in any country it should never feel hopeless. But they are very rare.

2) A good human being who helps others until it doesn’t hurt his or her own self.

3) A selfish person who hurts somebody for his or her own good.

4) A person who hurts other people without any reason or purpose. Just for hurting them.

The principle of Karma is at the very core of Shrimad Bhagavad Gita’s teachings. It’s called ‘Karma Yog’ by Krishna. I am very curious about whether it works or not! How much is it true for real life? Are there any measured results of it? Faith is a different thing and science is too. Can it be a topic for metaphysics? I am just curious.