Lady Macbeth:
She has a cold heart and strong willed. She has a cold heart because she doesn't seem to care about Duncan's death and how she does'nt mind smashing baby heads on floors while she is nursing them.Lines 59 to 63 , Act 1 Scene 7 show it to be so.

Duncan
Well, Duncan seems to be a very kind person. He is known throughout nature as being a kind king and has been known to be quick in trusting people. In Act 1, Scene 4 , Lines 13 to 16 he is speaking to Macbeth and shows how he is very quick to trust someone ' He was a gentleman on whom I built, An absolute trust.'   He is talking about  The Thane of Cawdor and is very dissapointed he has just gotten executed bacause he as a traitor.

Malcolm
Malcolm is the king's son. He is also quite smart and rational. There is one examples of this. The first example would be when he says in Act 2, Scene 3 , Lines 159-161 ' Let's not consort with them : To show an unfelt sorrow is an office Which the false man does easy. I'll to England.' Them, would be the nobles who were just discussing about the death of Duncan. Malcolm is speaking quitely to Donalblain and is scared that the person after his father would be after him as well. This shows him to be rational and a bit afraid for his life so he flees to England.