Evaluation strategies for some nonstandard conditionals during adolescence.

380 adolescents and young adults between the ages of 11 and 29 years participated in three experiments in which they were asked to evaluate both universally quantified nonstandard and standard conditionals using items of information bearing upon them. Subjects found it much easier to avoid a biconditional interpretation with the nonstandard than with the standard conditionals, which throws doubt on the explanation of desire for symmetry of biconditional conversion. It was argued, from data of other studies, that a modified version of the Piagetian view that biconditional conversion occurs as a result of a desire to avoid the complications of dealing with three factors explains most cases of such conversion in adolescence. Results also confirmed that it is more profitable to analyse performance on tasks of this kind using a two-stage model of interpretation and information use previously developed to explain performance with standard universally quantified conditionals than to view such tasks as providing truth-table values. Such an analysis was extended to the nonstandard conditionals studied in the present paper. The origins of the dramatic differences in information-use strategies adopted by adolescents for standard and nonstandard conditionals remain unclear.     

Rigidity, Occasional Identity and Leibniz' Law

André Gallois' recent book Occasions of Identity attempts to defend the coherence of the view that objects may be identical at one time but distinct at another (the occasional identity thesis). The defence requires a special account of rigid designation and a special version of Leibniz' law. This paper shows Gallois' proposals in this regard to be inadequate, and suggests a better line of defence for occasional identity theorists.     

Gender Differences in the Suicide-Related Behaviors of Adolescents and Young Adults

Gender differences in suicide-related behaviorswere examined in an older adolescent and a young adultsample (primarily Caucasian). Suicide-related behaviorswere assessed by the Life Attitudes Schedule (LAS) as well as by measures of depressivesymptomatology and hopelessness. The LAS measures a broadcontinuum of potentially life-diminishing orlife-enhancing behaviors. There are four LAScontent-category subscales: overtly suicidal and death-related,self-related, risk and injury-related, and health-relatedbehaviors. As hypothesized, in both samples, genderdifferences in the expression of suicide-related behaviors were obtained. Males from both samplesendorsed substantially more risk-taking andinjury-producing behaviors than females. Males in bothsamples also reported more negative health-relatedbehaviors than females. In contrast, females reported moresymptoms of depression than males. Hopelessness scoresonly differentiated male and female young adults; maleand female adolescents did not differ significantly on the hopelessness measure. These findings areprimarily discussed in terms of gender-role socializationtheory. Implications for the treatment of suicidality aredrawn.     

A defence of anti-criterialism

According to philosophical orthodoxy, there are informative criteria of identity over time. Anti-criterialism rejects this orthodoxy and claims that there are no such criteria. This paper examines anti-criterialism in the light of recent attacks on the thesis by Matt Duncan, Sydney Shoemaker and Dean Zimmerman. It is argued that those attacks are not successful. Along the way, a novel strategy to defend anti-criterialism against the critics’ most challenging objection is developed. Under-appreciated difficulties for criterialism are also raised which, I claim, there is no obvious way to solve. It is concluded that anti-criterialism may be a much stronger rival to criterialism than is often supposed.     

Assessing functions of stimuli associated with rich‐to‐lean transitions using a choice procedure

Under fixed‐ratio schedules, transitions from more to less favorable conditions of reinforcement (rich‐to‐lean transitions) usually generate extended pausing. One possible explanation for this effect is that stimuli associated with rich‐to‐lean transitions are aversive and, thus, extended pausing functions as escape. The purpose of this study was to characterize further the aversive function of different transitions, and the stimuli associated with them, by allowing pigeons to choose to complete select ratios in the presence of either a mixed‐schedule stimulus or a transition‐specific multiple‐schedule stimulus. The mixed schedule was preferred during transitions that signaled an upcoming lean reinforcer (rich‐to‐lean and lean‐to‐lean), whereas the multiple schedule was preferred during transitions that signaled an upcoming rich reinforcer (lean‐to‐rich and rich‐to‐rich). These findings support the notion that stimuli associated with rich‐to‐lean (and to some extent lean‐to‐lean) transitions can function aversively; whereas stimuli associated with other transitions (e.g., lean‐to‐rich and rich‐to‐rich) can function as conditioned reinforcers. When the opportunity to choose between schedule‐correlated stimuli was available, however, choice latency was controlled exclusively by the multiple‐schedule stimulus. That is, the opportunity to select the mixed schedule did not attenuate rich‐to‐lean pauses, suggesting that extended pausing may be more than simply escape.