Jealousy and honesty

So where is the line drawn between jealousy and honesty. Are people ever just truly honest, or does our true human nature make us envy what other people can do better than us, so we just put them down. For example, when Kanye told Taylor Swift she did not deserve to win, it is funny that he said Beyonce should have won. I feel like he was just jealous that a new artist won, and he did not even get a nomination. I mean, it is not her fault that he is a dying artist and basically no one listens to him anymore. Also, when kids who do AP and hate IB, talk poorly about IB, is it because they are jealous that we can handle a hard class in every subject, and have grade point averages through the roof, or do they just honestly think AP is better? Well I think they are jealous, since AP is specialization, and I thought that was what you are supposed to do in college when you pick a major. In conclusion, I think that our human nature causes us to be brutally honest when we are truly envious of someone else.