Chewing gum

Was wondering around the other day and it occurred to me, chewing gum(the act) is something you can't do(or will not want to do) when you are sad. Feels like a inherently happy(state) thing to do. So was wondering if you can use this as a litmus test to figure out if someone is angry/sad by offering it(the Gum) and seeing if they are indeed chewing or not? Viners! Chime in.