A dementia determination system (100) includes: an acquisition unit (111) configured to acquire a long press ratio which is a ratio of a number of long presses in which a button of an operating device (140) is pressed for a time longer than a reference time, to a number of presses of the button of the operating device (140) used by a user to operate an electric device (130)； a determination unit (112) configured to determine a dementia level of the user based on the long press ratio acquired by the acquisition unit (111)； and an output unit (113) configured to output dementia information indicating the dementia level determined by the determination unit (112), wherein the determination unit (112) is configured to determine that the dementia level is more severe as the long press ratio is lower.
