Thermal Changes in Palmar Skin Resistance Patterns

In contrast to the usual description of a uniformly low basal skin resistance at the human palmar surface as compared with other parts of the body (Richter, Woodruff, & Eaton, 1943; Wilcott, 1963), the present studies reveal skin resistance patterns (SRPs) with different resistance values at different subregions of palm and forearm. The shape of these patterns is related to the season in which the experiment was performed. Three basic SRPs are described, for winter, summer, and prolonged summer heat spell, respectively: (a) an alternating pattern, (h) an oblique pattern, (c) a so‐called summer reversal pattern. The distinguishing factor for this categorization is the reciprocal electrodermal behavior of the mid‐palm and arm regions. The resistance of the palm is relatively low in the winter, intermediate in the early summer, and high in a summer heat spell, while the resistance of the arm is high in winter and summer and low in the heat spell. Experimental heating and cooling leads to independent variation of the skin resistance values at different subregions and differs as a function of the basic seasonal SRP. A follow‐up study shows that children have a less differentiated pattern, which, at all seasons tested, is similar to the oblique summer pattern of adults. The studies are considered exploratory.