Delay reduction: current status.

Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond the effect exerted by frequency of primary reinforcement.     

Children's strategies for coping with stress: Blunting and monitoring

The present study examined children's suggestions for coping with uncontrollable stress, from the perspective of the monitoring/blunting distinction proposed by Miller (1987). Children in the first through sixth grades heard stories depicting four stressful situations that afforded little opportunity for control. Children's coping suggestions were classified as blunting (including reappraisal, cognitive distraction, and behavioral distraction), monitoring, or seeking support. Overall, blunting strategies were mentioned most often, followed by monitoring, and seeking support. A grade-level increase in blunting suggestions was found, and this developmental pattern was identical for reappraisal, cognitive distraction, and behavioral distraction. No grade-level differences were observed for monitoring or support. Situational differences in coping suggestions were explored, and there was mixed evidence of cross-situational consistency in coping style.The author would like to thank the staff and students of the Bell Top Child Care Centers and Kinder-Care Learning Center, Bloomington-Normal, Illinois. Thanks are also due to Cricket Blassage and Latoria Carroll for their help with the coding. This research was partially supported by a small grant from Illinois State University. An earlier version of this paper was presented at the meeting of the Society for Research in Child Development, Seattle, Washington, April, 1991.     

Timeout from concurrent schedules.

Response-contingent timeouts of equal duration and frequency were added to both alternatives of unequal concurrent schedules of reinforcement. For each of 4 pigeons in Experiment 1, relative response rates generally became less extreme as the frequency of timeout increased. In Experiment 2, relative response rates consistently approached indifference as the duration of timeout was increased. Variation in time allocation was less consistent in both experiments. Absolute response rates did not vary with the timeout contingency in either experiment. In a third experiment, neither measure of choice varied systematically when the duration of a postreinforcement blackout was varied. In contrast to the present results, preference has been shown to vary directly with the parameters of shock delivery in related procedures. The pattern of results in the first two experiments follows that obtained with other manipulations of the overall rate of reinforcement in concurrent schedules. The results of the third experiment suggest that an intertrial interval following reinforcement is not a critical feature of the overall rate of reinforcement.     

Externalism and first-person authority

Externalism in the philosophy of mind is threatened by the view that subjects are authoritative with regard to the contents of their own intentional states. If externalism is to be reconciled with first-person authority, two issues need to be addressed: (a) how the non-evidence-based character of knowledge of one's own intentional states is compatible with ignorance of the empirical factors that individuate the contents of those states, and (b) how, given externalism, the non-evidence-based character of such knowledge could place its subject in an authoritative position. This paper endorses a standard strategy for dealing with (a). The bulk of the paper is devoted to (b). The aim is to develop an account of first-person authority for a certain class of intentional states that is capable of explaining (1) why knowledge of one's own intentional states is peculiarly authoritative, and (2) why such authority is compatible with externalism.     

Positive modal logic

We give a set of postulates for the minimal normal modal logicK ₊ without negation or any kind of implication. The connectives are simply , , , . The postulates (and theorems) are all deducibility statements . The only postulates that might not be obvious are

Patterns of mother-infant interaction and attachment: A cluster-analytic approach

This study examined stability and change in patterns of mother-infant interaction between 5 and 10 months and their relation to attachment security at 18 months. Cluster analysis was used to identify patterns of dyadic interaction. There was significant, but not substantial, stability in cluster membership from 5 to 10 months. For females, being in the most optimal cluster at 5 months related to subsequent attachment security, regardless of the 10-month pattern of interaction. For males, who were significantly more likely to be insecure than females, insecure attachment was predicted by negative change from 5 to 10 months (moving from a more optimal to a less optimal cluster).     

The assessment of cortisol using salivary ultrafiltrate

Cortisol can be used to indicate stress level as well as to monitor certain disease states. Although cortisol can be sampled from blood and urine, saliva sampling has decided advantages. Unfortunately, whole saliva contains a number of substances that can metabolize or bind with cortisol, potentially confounding analysis and quantitation. We introduce a semipermeable pouch that accumulates a contaminant-free salivary ultrafiltrate, thereby overcoming a number of the problems encountered with whole saliva. In three studies, we demonstrate accuracy and utility of the device for cortisol determination: (1) in an artificial medium, 60%–77% of the cortisol was recovered in the ultrafiltrate; (2) in vivo, ultrafiltrate cortisol correlated highly with whole-saliva cortisol collected under ideal conditions; and (3) ultrafiltrate cortisol evinced positive relationships with depression and cigarette use, consistent with studies in the literature. We conclude that this device and saliva-filtering technologies in general are useful in applications requiring quantitation of cortisol.     

Male-female differences in sexual fantasy

A questionnaire about thoughts and ideas during sexual activity was returned by 51 females and 50 males in a random sample of college undergraduates. A high response rate (91%) and the similar sexual experience of male and female respondents make possible a strong conclusion about the college population sampled: Males are thinking more about past experiences and current behavior, while females are thinking more of imaginary experiences. This difference occurs for thoughts during masturbation as well as for thoughts during heterosexual activity. It appears that females prefer a different kind of sexual fantasy than males, rather than being generally less interested in sexual fantasy as claimed by Kinsey, Pomeroy, Martin, and Gebhart (Sexual behavior in the human female, Philadelphia: Saunders, 1953).