In investigating emotional phenomena in humans, overt-behavioral, self-report, and physiological responses all often seem to be appropriate measures. However, experience has shown that these different kinds of response often do not vary together. It may be that these measures disagree because they are related to different underlying variables. To illustrate how overt-behavioral and physiological responses appear to be influenced by different kinds of variables, several studies of sex differences in emotional responding are reviewed. These indicate that, in certain emotional situations, females appear to respond more than males on overt-behavioral measures, while males show larger physiological responding. In situations involving aggression, in contrast, males show more overt responding while females show greater physiological reactions. The data suggest that the overt-behavioral responses are in fact affected directly by social expectations, while the physiological measures are not. It is concluded that different sets of variables must underlie overt-behavioral and physiological responses, and that the relationships between different kinds of emotional responding deserve further study. (Author/TA)