What counts as an answer to the question “Why did Person A do Action X?” Below is a first cut at a list of possible answers to that question. The fact that it has only thirteen elements would make it interesting if it were comprehensive. I’m quite deliberately eliding the behavior/action distinction here, looking for a list that will include intentional, unintentional, and truly involutary behaviors.
1. Reflex (jumping at a loud noise).
2. Compulsive behavior (tics, stammers, etc.)
3. Need (air, water, food, etc.), including acquired needs such as addictions. Defined by unpleasant sensation of lack, relieved by doing X.
5. Custom (others do X).
6. Pleasure (X is enjoyable).
7. Advantage (perceived gain accruing from doing X: material or ideal, including status or relational gain, for self or other).
8. Fear (of the consequences – again for selff or another – of not doing X, including status or relational loss).
9. Duty (as distinct from positive or negative social consequences of doing or not doing X).
10. Role aspiration (wanting to be the sort of person who does X, again as distinct from the social consequences).
12. Inadvertence (e.g., stumbling over something, or being pushed).
What did I leave out? And who has done this analysis already?