Subject characteristics and situational variables of bilateral electrodermal activity were investigated. Three parameters of electrodermal activity were considered - directionality of body side of higher skin resistance, magnitude of differences in bilateral skin resistance, and asymmetry of bilateral skin resistance movement. Forty-nine right handed subjects participated in the experiment, in which skin resistance was recorded simultaneously from the left and right hands during a 20 minute baseline and a series of arousing tasks. Two tasks were left hemisphere-specific, two tasks were right hemisphere-specific and three tasks were not hemisphere-specific. Of 44 subjects considered, 26 had higher left side skin resistance, 10 had higher right side skin resistance and 8 showed no significant difference of skin resistance between the two hands. Eye dominance influenced the directionality of body side of higher skin resistance. Right-eyed individuals were more likely to show higher skin resistance on the left side than were left-eyed individuals. Neither directionality of body side of higher skin resistance nor the magnitude of bilateral skin resistance differences could be predicted on the basis of a number of personality and physiological variables which included sex, locus of control, preferred cognitive mode, mode of defence mechanism, frequency of spontaneous skin resistance fluctuations and left/right skin resistance correlation. Contrary to expectation, predictable asymmetry of bilateral skin resistance movement did not occur in response to unilateral hemispheric activation or changes in arousal state. However when subject skin resistance data were analysed individually, significant asymmetry of bilateral skin resistance movement occurred during the course of the experiment for 17 of 40 subjects considered. The results of the study were discussed in terms of a possible mechanism of skin resistance.