what makes one tick

What makes one function characteristically, what motivates one, as in We've never figured out what makes these chess players tick. This expression alludes to tick in the sense of "function as an operating mechanism, such as a clock." [Colloquial; first half of 1900s]

Common Names:

Name	Pronounced	Usage
Philippos	-	Ancient Greek, Biblical Greek
Eutropius	-	Ancient Greek (Latinized)
Nia (1)	-	Welsh
Phocas	-	Ancient Greek (Latinized)
Rodolphe	-	French
Karam	-	Arabic