halfhearted, lukewarm, tepidapathetic, casual, complacent, disinterested, incurious, indifferent, insensible, insouciant, nonchalant, perfunctory, pococurante, unconcerned, uncurious, uninterestedaloof, cold, numb, remote, unemotionalcallous, hard-hearted, insensitive, unfeelingcalm, cool, detached, dispassionatecareless, heedless, mindlessimpassive, impervious, phlegmatic, stoic(or stoical), stolidlethargic, listless

concerned, interested, impressedattentive, aware, conscientious, heedful, mindfulcaring, sensitive, warmheartedardent, fervent, impressed, keen, passionate, warm, zealous