A pilot study is proposed to explore individual differences in the ability to learn to self-regulate skin temperature. Skin temperature is chosen as a model for autonomic learning because replicated, reliable results have been reported of magnitudes sufficient to imply potential medical applications. It is hypothesized that the ability to learn to self-regulate vasomotor responses is a partial function of psychophysiological reactivity and normal control. Questionnaires of autonomic reactivity and control have been constructed by factor analytic methods from a pool of over 500 subjects. Subjects scoring high and low on the three scales derived are being evaluated for baseline variability in skin temperature, untrained ability to control skin temperature and reactivity. From these subjects, sub-samples will be evaluated to assess their ability to learn to control skin temperature.