The study proposes a method to measure the likelihood for target people to take prosocial behavior using their objective physiological data as well as Prosocial behavior means attempts to help others without expecting any external reward. Conventional methods use questionnaires to identify people with a strong likelihood to engage in prosocial behavior. The conventional methods impose an undesirable burden on them because the questionnaires on prosocial behavior are unusual to them. To avoid the unusuality, the proposed method makes people listen to heart-breaking music, recording a time series of their electrodermal activities (EDA), which are physiological responses expressing their emotional changes. An experiment turns out people likely to take prosocial people would show emotional responses to both acoustics and lyrics. An experiment turns out people likely to take prosocial people would show emotional responses to both acoustics and lyrics.