Helson's Residual Factor versus Innate S-R Relations
As indicated by the diversity and number of studies (see, for example, Beach & Jaynes, 1954; Bovard, 1958; King, 1958), investigators have given abundant explicit recognition to the weight of the variable of early experience. They have concluded that the organism is extremely plastic during its infancy and youth such that the increased experience effects irreversible and advantageous changes in his behavior during maturity. Some have discussed these phenomena in terms of Adaptation Level Theory, specifically Helson's residual factor, R, (e.g., Meier & Stuart, 1959), but none has devised an experience sufficiently amenable to later testing procedures that this particular theoretical formulation can have adequate evaluation (e.g., Meier & McGee, 1959). Greatly simplifying Helson's psychophysics, we made just such an attempt in this study.' Two groups of CF/1 male mice were raised from weaning (25 days) under controlled conditions of illumination. One group ( N = 8 ) was reared under conditions of flashing light (GO flashes per sec.); the other group ( N = 8) was reared under constant illumination. All animals were maintained on a 12-hr. light: 12-hr. dark cycle. The illumination fluctuated between .5 and 3.2 footcandles for the experimental group; the illumination was 3.2 footcandles for the control group. When about 90, 97, and 104 days of age, Ss were tested for preference of illumination conditions. Each S was placed, individually, in a compartment 5 in. X 7% in. X 9 in. deep, illuminated in the manner of his rearing environment. From this compartment, S could freely move to a second compartment, identical to the first save that the illumination was that of the other environmental condition. The time spent in each of the two compartments was recorded for a 60-min. interval at each of the three ages. For purposes of analysis, however, the behavior during each 30-min. period was examined. The two groups differed in the preferences only on the first half of the second test session. In all other sessions, both groups strongly preferred the constant to the flashing condition.