Effects of cocaine on briefly signaled versus completely signaled delays to reinforcement.

Key pecking by 4 pigeons was maintained by a multiple schedule consisting of two variable-interval 60-s schedules wherein each food presentation followed a nonresetting 27-s delay that was either briefly signaled at its outset or completely signaled. Brief-signal duration was adjusted so that response rates maintained by the briefly and completely signaled delays of reinforcement were similar. In general, acute administration of small to intermediate doses (0.3 to 3.0 mg/kg) of cocaine produced either small increases in response rates in both components or no change, and larger doses (5.6 to 13.0 mg/kg) decreased response rates. Chronic (i.e., daily) cocaine administration (10.0 mg/kg) resulted in tolerance to the rate-decreasing effects in both components. Cocaine's effects were generally similar whether delays were completely or briefly signaled. Discontinuation of cocaine administration and subsequent removal of the delay signals also had similar effects in both components of the multiple schedule. Taken together, these results are consistent with the view that the two types of delay signals were equally effective in maintaining responding during the variable-interval schedules.     

Tolerance to and residual effects of cocaine in squirrel monkeys depend on reinforcement-schedule parameter.

Lever pressing by 4 squirrel monkeys was maintained under a three-component multiple fixed-ratio schedule of food presentation; components differed with respect to ratio size. For each monkey, acute administration of cocaine (0.03 to 1.3 mg/kg, i.m.) produced dose-dependent decreases in overall response rate in each component. During repeated daily administration of 1.0 mg/kg of cocaine, tolerance developed to the rate-decreasing effects under each of the ratio contingencies, but developed to a greater extent and was evident in earlier parts of sessions for performance under the smaller ratios. Response rates of 2 monkeys increased above nondrug control levels despite the putative reinforcer not being consumed during the session. When saline or a smaller dose of cocaine was substituted for 1.0 mg/kg, response rates often were suppressed below nondrug control-level responding. This suppressive effect was observed in each monkey and was more likely to be observed and/or to be of greater magnitude in large-ratio components for 3 of the 4 monkeys. When saline was administered chronically at the end of the chronic-drug phase, response rates remained suppressed in the large-ratio component for 2 of the monkeys. There was, therefore, a schedule-dependent dissociation between behavioral tolerance and the residual effects: Tolerance was greater when small ratios were arranged, whereas the residual effects were more pronounced when larger ratios were arranged.     

A reappraisal of the relation between performances of quantitative identity and quantitative equivalence conservation tasks

Previous studies of children's performance on quantitative identity and equivalence conservation problems in the number domain are suggested to be flawed because of the low numbers of items in the arrays. In Experiment 1, children were tested on three different number versions of identity and equivalence conservation tasks. Their performance varied with the number of items and no child was found to pass a large number version of an equivalence conservation task and fail the corresponding version of an identity conservation task. In Experiment 2 the notion that the contextual effect of asking two similar questions might underlie the difference in performance on the two tasks was tested and rejected. The results are discussed in relation to recent analyses of conservation problems.     

The effects of exposure to political and domestic violence on preschool children and their mothers

The purpose of this study was to examine the effects of exposure to political violence on preschool children and their mothers. We explored whether these dyads are different from dyads with no known history of exposure to violence and from mother–child dyads with known exposure to domestic violence. Specifically, we explored differences in mothers' psychological status (depression and anxiety), dyadic emotional availability (EA), children's social information processing, and children's social behaviour, in a sample of 216 dyads divided into three groups (exposure to political violence, no exposure to violence, and exposure to domestic violence). We found evidence to support our hypotheses that children exposed to domestic violence exhibit the highest levels of social maladjustment with smaller but still significant differences between children exposed to political violence and children in the comparison group. As expected, the lowest EA scores were found in the exposure to domestic violence group, followed by dyads in the exposure to political violence group. Dyads belonging to the comparison group (no exposure) exhibited the highest levels of EA. These findings contribute to our understanding of the meaning of exposure to political violence, as well as sharpen the difference between exposure to political and domestic violence.     

The Politics of Choice: Political Ideology and Intolerance of Ambiguity

The authors examine how political ideology impacts consumer preferences for hedonic and utilitarian choices and the underlying reasons for these differences. Five studies indicate that conservatives are less tolerant of ambiguity than liberals, leading to a preference for utilitarian options, whereas liberals are more tolerant of ambiguity leading to a preference for hedonic options. However, these preferences were reversed when utilitarian options were framed as ambiguous and hedonic options were framed as explicit and clear.     

Providing noncontingent,alternative, functional reinforcers during delays following functional communication training

Functional Communication Training (FCT) involves arranging extinction for problem behavior and reinforcement for a more desirable, functionally equivalent, communicative response (FCR). Although effective under ideal arrangements, the introduction of delays to reinforcement following the FCR can result in increased problem behavior. Austin and Tiger (2015) showed that for individuals whose problem behavior was sensitive to multiple sources of reinforcement, providing access to alternative, functional reinforcers during delays mitigated this increase in problem behavior during delay fading. The current study replicated the procedures of Austin and Tiger with 2 individuals displaying multiply controlled problem behavior. Providing alternative functional reinforcers reduced problem behavior during 10-min delays for both participants without requiring delay fading.     

Distancing or drawing together: Sexism and organisational tolerance of sexism impact women's social relationships at work

This article examines the role of organisational climate in women's social responses to sexism at work. We argue that after experiences of sexism, women “draw together” with other women when they perceive that the organisational climate is intolerant of sexism. We assess the role of organisational climate at three levels: peer-, manager-, and policy-level. We conducted a correlational study (N_study1 = 405) and two experimental studies (N_study2 = 377, N_study3 = 391), in which we examined women's experiences of sexism at work (measured in Study 1; manipulated in Studies 2 and 3). We also measured perceived tolerance of sexism at the peer-, manager- and policy-level in all studies. The main DVs were women's workplace friendships with other women in Studies 1 and 2, and closeness to female co-workers in Study 3. Results showed that perceived tolerance of sexism from peers was especially important in shaping women's social relationships following experiences of sexism; tolerance from managers or at the policy level had less consistent effects. Specifically, experiences with sexism were positively associated with female participants' reported friendship (Studies 1 and 2) and closeness (Study 3) with their female colleagues, but only when peers were perceived not to tolerate sexism. When peers were perceived to tolerate sexism, female participants did not respond to sexism by drawing together.     

MORPHINE TOLERANCE AS A FUNCTION OF RATIO SCHEDULE: RESPONSE REQUIREMENT OR UNIT PRICE?

Key pecking by 3 pigeons was maintained by a multiple fixed-ratio 10, fixed-ratio 30, fixed-ratio 90 schedule of food presentation. Components differed with respect to amount of reinforcement, such that the unit price was 10 responses per 1-s access to food. Acute administration of morphine, l-methadone, and cocaine dose-dependently decreased overall response rates in each of the components. When a rate decreasing dose of morphine was administered daily, tolerance, as measured by an increase in the dose that reduced response rates to 50% of control (i.e., the ED50 value), developed in each of the components; however, the degree of tolerance was smallest in the fixed-ratio 90 component (i.e., the ED50 value increased the least). When the l-methadone dose-effect curve was redetermined during the chronic morphine phase, the degree of cross-tolerance conferred to l-methadone was similar across components, suggesting that behavioral variables may not influence the degree of cross-tolerance between opioids. During the chronic phase, the cocaine dose-effect curve shifted to the right for 2 pigeons and to the left for 1 pigeon, which is consistent with predictions based on the lack of pharmacological similarity between morphine and cocaine. When the morphine, l-methadone, and cocaine dose-effect curves were redetermined after chronic morphine administration ended, the morphine and l-methadone ED50s replicated those obtained prior to chronic morphine administration. The morphine data suggest that the fixed-ratio value (i.e., the absolute output) determines the degree of tolerance and not the unit price.     

Living with Contradictions: The Taken-for-Granted in Israeli Political Discourse

Two apparently contradictory ideas are closely linked in Israeli political discourse: Israel is powerful and independent and Israel is vulnerable and dependent. This study used content analysis and focus groups, as well as existing survey data analyzed by others, to explore how this paradox has been reflected in newspapers and conversations during six different time periods from 1948 to 1996. The goal was not to explain the paradox but to examine its consequences for Israeli perceptions of U.S. policy in the Middle East—and, in the process, to explore Israeli self-images. The nature of U.S. strategic interests was originally treated as problematic and in need of political discussion, but in the past 25 years these interests have become taken for granted. Surprisingly, even after the end of the Cold War, a critical discourse moment in which a reexamination of U.S. interests in the Middle East would seem inevitable, the U.S. role remains taken for granted and largely unexamined. The strong/vulnerable paradox explains this absence of discussion: Examining U.S. interests too closely upsets the delicate balance that keeps the sense of vulnerability in check.     

Does Differential Cohort Socialization Matter? The “Age Invariance” Hypothesis and Political Socialization

In classical and contemporary social theory alike, the key to understanding how cultural change comes about has been thought to lie in the long-term effect of differential cohort socialization. Cultural change is thought to proceed as differently socialized cohorts replace each other in the course of time. Moreover, distinct generations have been claimed to emerge. Thisarticle addresses the impact of cohort replacement and the presence of generations, including discussions of the theoretical framework underlying these concepts and the problem of disentangling age, period, and cohort effects. Analyses of Dutch survey data substantiate that cohort membership matters. Yet the impact of cohort replacement on cultural change turns out to be limited, and little evidence is found in support of the idea that specific generations arediscernible.