'reward-responsive' is a modern English compound formed from 'reward' + 'responsive' (created in scientific/technical contexts to describe reactions to rewards).

'reward' comes from Middle English (from a verb sense meaning 'to regard or to recompense'), while 'responsive' derives from Latin 'respondēre' via Old French/Latin roots into English as 'responsive' in the 17th century; the compound 'reward-responsive' arose in modern English by combining these two elements.

Initially, the separate elements referred to 'a recompense' ('reward') and 'able to respond' ('responsive'); combined in recent usage they mean 'able to respond to rewards' specifically (used especially in behavioral and neuroscientific contexts).