I'm stepping away from the ol' computer for now...so won't hazard a long answer to your very good question. But, though I have no research in hand, I don't see emotion as lineal...and there's just too many qualities of emotion. And thinking and emotion operate out of different parts of the brain. And "they" don't understand each other very well...

But I do recall seeing something once, a long time ago, about how laughter is a lot easier on you than many other emtions...but I will have to go digging on that...

"Once in awhile we get shown the light, in the strangest of places, if we look at it right" - Hunter/Garcia