My sim Eva DuPont did another funny thing whilst I was playing last night. Again, I don't know if this happens all the time or it's just my sim. I swear over time the sims develop a personality of their own (which is a very scary AI thought!).
Anyhow, just to mention the traits again, they're Athletic, Disciplined, Adventurous, Genius, and Brave. This time she was chatting away on the computer to her best friend, and I was wandering over the house thinking of redecoration when I heard all this grumbling from her. So I centred on my sim and there she was grumbling away and getting angry, and bashing the mouse and keyboard. The look on her face was priceless. Thing is she does not have the hot-headed trait. First her throwing a hissy fit for failing a fire trap, now getting angry at the computer.
Oh, and just thought of another situation, with the same sim. When she was in China having dinner at her boyfriends house with him and his sister when halfway through the dinner both the boyfriend and sister stood up and proceeded to point and laugh at my sim for a full half hour. What's up with that? I know all his traits and none of them suggest this.