Performance of humans in variable-interval avoidance schedules programmed singly, and concurrently with variable-interval schedules of positive reinforcement

Performance maintained under single variable-interval avoidance schedules, single variable-interval schedules of positive reinforcement, and concurrent schedules consisting of a variable-interval avoidance component and a variable-interval positive reinforcement component, was studied in three human subjects, using points exchangeable for money as the reinforcer. Response rate in the single variable-interval avoidance schedules was an increasing function of the frequency of monetary loss avoidance. Response rate in the single variable-interval positive reinforcement schedules was an increasing function of the frequency of obtained monetary reinforcement. In the concurrent avoidance/reinforcement schedules, the rate of responding in the avoidance component increased, and the rate of responding in the positive reinforcement schedule decreased (with one exception) as a function of the frequency of loss avoidance in the avoidance component. The logarithms of the ratios of the response rates in the two components, and the logarithms of the ratios of the times spent in the two components, were linearly related to the logarithms of the ratios of the frequency of loss avoidance in the avoidance component to the frequency of reinforcement in the positive reinforcement component. All three subjects exhibited marked undermatching of response rate ratios to reinforcement frequency ratios. The results are discussed in the context of Herrnstein's quantitative model of operant performance.     

Sex Bias in Clinical Judgment: Later Empirical Returns

This paper updates an earlier review of research on sex bias in psychological evaluation and psychotherapy. The experimental analogue continues to dominate the literature and to return a resoundingly negative verdict. This evidence, however, is often discounted on the grounds of the analogue's transparency and clinical impoverishment. Naturalistic data have likewise failed to support claims of widespread sex bias, but have nonetheless whetted suspicions that gender and sex role attributes affect circumscribed clinical decisions. These correlational field studies are often dismissed, however, on the basis of their inadequate control for potential confounds. This empirical deadlock is discussed within the context of the sexual politics of research and of methodological preference in particular. The interpretive gerrymandering that has plagued this literature is linked to an unwillingness to be open about the sex role heritage of research strategies themselves and the deep personal and political investments at stake.