Well here goes anyway. Adolescence is a time of discovery. The boys set off on a journey not so much to see a cadaver as to find out about themselves. One tries out the gun, another sees how far he can push danger with the train, another learns to share his emotions about his family with his friend.
Ethics are also something to try out and learn about.
Adolescence is a time of trying out ethics too, and learning about the unethical behavior of adults.