Definition
Plain language
How energized or worked-up a feeling is, from calm and sleepy on one end to alert and intense on the other.
As stated in the literature
One of the two principal axes psychologists use to map emotional states (paired with valence), spanning low to high activation; recovered as a dominant axis in the geometry of a model's learned emotion vectors.
Why it matters: It is one of the two basic dials that organize emotional states, so capturing it helps a model represent feelings in a structured, comparable way.
For example, both being terrified and being thrilled are high-arousal states, while feeling bored or relaxed sits at the low-arousal end.
Heard on the show
“And arousal — calm to activated.”Episode 006 — What Happens Inside Claude When It Decides to Blackmail Someone