Hamlet shows human nature to be greedy, self-involved and vengeful. Claudius is driven by his own greed to commit murder. Polonius is always looking out for himself. Hamlet thinks of vengeance from the moment he finds out about Claudius killing his father. Human nature has been all of these things, but it has also changed through the ages. We can be cruel, but we can also show great compassion and kindness.
Claudius kills his own brother so that he can claim the crown and the Gertrude.
He gets rid of a good king to satisfy his greed. He kills his own brother, the good of the country, and the happiness of most of the characters in the play to fulfill his desire of being king. He cares only for himself. Most people at one point or another will be driven by greed. Most humans will not have the desperation that Claudius shows in Hamlet. Greed is part of all everyone. It's just they way people choose to deal with that feeling or if they feel is what separates many from Claudius. They see something they want and they tell themselves that it is only what they deserve. It is inevitable but we can control it to a certain degree I think.
Polonius shows the characteristic of human nature that is self-concern. He is always looking for ways to get closer to the king. He sacrifices his own daughter's happiness so that he can prove his theories about Hamlet's madness to the king. Self-concern is another trait that humans cannot seem to avoid. People are constantly thinking about themselves and how things are going to affect their lives. They care deeply for their own well being. Certainly they think about others occasionally, but their own person is always number one in their minds.
Vengefulness is yet another human trait. Hamlet's