High levels of arousal are unstable.

When sufficiently aroused, and in the right setting, love for something can quickly change to great dislike, or fear can convert to pleasurable feelings. Roller coasters provide a fine demonstration of the latter. [And the former -- The Roller Coaster of Love] Just before that first drop, arousal is high and the emotional valence is negative – "Oh, my gawd... I’m gonna DIE!" -- but as soon as the mind and body realize that there is no real danger, fear turns to pleasure.

And what’s with "THE VILLAIN YOU LOVE TO HATE!," hmm? In the film The Silence of the Lambs, Hannibal Lector radiates danger, but when it becomes clear that he represents no real threat to the audience or any character the audience likes or relates to, his perverse acts become entertaining.

These are occasions of high arousal. When arousal is small, affect is small. However, frustration with an application, if frequent, can quickly raise a user’s level of arousal and with strong negative valence.

Fortunately, if the user is experiencing positive affect, whether simple pleasure in one’s work or excitement at accomplishing a task, the level of arousal is of little concern. However, if your application is intentionally arousing, try to make sure nothing tips affect from positive to negative.