Same word as reactive:

acknowledging, active, alive, answering, awake, aware, compassionate, conscious, forthcoming, impressionable, influenceable, kindhearted, open, passionate, perceptive, persuadable, reactive, receptive, replying, respondent, sensible, sensile, sensitive, sentient, sharp, softhearted, susceptible, susceptive, sympathetic, tender, warm, warmhearted