Intelligent people can be good and responsible beings but also the other way around. There are a lot of intelligent people who are criminals, even murderers. In the end they are humans, weak, strong, sick or healthy. Some of them are only partially intelligent, they are good in one field but barely cannot survive in real life. Some are confused, disturbed.

An intelligent man working at Intel in Germany decided to meet with a cannibal to end his life that way, how intelligent is this?

But in the end I am sure that most of them are good and responsible (with or without a religion as a backup).