Heart rate and electrodermal responding were monitored while subjects scoring high or low on the Internal-External Locus of Control Scale (I-E Scale) and high or low on the Interpersonal Trust Scale (IPTS) viewed 10 repeated presentations of a visual orienting stimulus. Collapsing over all 10 stimulus trials, subjects scoring at the External end of the I-E displayed a significant decrease in heart rate change. During the first trial of stimulus presentation, subjects who were External on the I-E and low on the IPTS displayed an immediate decrease in heart rate that reached its lowest point 2 sec after stimulus onset. In contrast, all other groups of subjects displayed an initial slight increase in heart rate during the first few seconds of the first stimulus, followed by a decrease in heart rate that reached its nadir between 4 and 6 sec after stimulus onset. The electrodermal results were similar to those obtained for the heart rate variable. It is suggested that Externals are more attentive to nonsignal environmental stimuli than Internals and that subjects low in interpersonal trust are more perceptually vigilant than those high in interpersonal trust. © 1987.
McCanne, T. R., & Lotsof, E. J. (1987). Locus of control, interpersonal trust, and autonomic responding during visual orienting. Journal of Research in Personality, 21(1), 40–51. https://doi.org/10.1016/0092-6566(87)90024-9