The development of young children's awareness of logical inconsistencies

Research by Markman (1979) suggests that children up to 12 years of age do not spontaneously detect logical inconsistencies. The present study was directed to factors which may limit children's ability to recognize their failures to understand. A task was devised which involved materials that were clearly based on children's experiences, and which involved premises and conclusions which were presented contiguously, rather than being interspersed among other sentences. Ninety-six 5-, 6-, and 7-year-old children were asked to judge the acceptability of eight three-sentence “stories” told by a puppet, and were asked to justify their responses. The stories differed in whether they were consistent or inconsistent, and in whether the principle upon which a story's consistency depended was implicitly or explicitly stated. The results showed developmental differences. By Age 7 years, most children were quite capable of evaluating sentences for their logical consistency. Five-year-olds, however, did not perform as well on the task, especially when the information upon which the logical cohesiveness of the stories rested was implicitly, rather than explicitly, stated. An examination of the justifications provided by these children revealed that they tended to question the empirical validity of individual sentences, rather than integrate the story as a whole and examine its overall logical structure.     

Nondeterministic three-valued logic: Isotonic and guarded truth-functions

Nondeterministic programs occurring in recently developed programming languages define nondeterminate partial functions. Formulas (Boolean expressions) of such nondeterministic languages are interpreted by a nonempty subset of {T (“true”), F (“false”), U (“undefined)}. As a semantic basis for the propositional part of a corresponding nondeterministic three-valued logic we study the notion of a truth-function over {T, F, U} which is computable by a nondeterministic evaluation procedure. The main result is that these truth-functions are precisely the functions satisfying four basic properties, called \( \subseteq \) -isotonic, \( \subseteq \) ^?-isotonic, hereditarily guarded, and hereditarily guard-using, and that a function satisfies these properties iff it is explicitly definable (in a certain normal form) from “if..then..else..fi”, binary choice, and constants.     

Children's representation of knowledge in verification

Thirty-two children aged 8–9 and 10–11 were asked to perform two statement verification tasks. Task 1 consisted of statements that were likely to elicit an affirmative knowledge representation,You have three eyes, is likely to elicit the representation,I have two eyes. Task 2 consisted of statements that were likely to elicit a negative knowledge of representation,You have a tail, is likely to elicit a negative representation,I do not have a tail. All statements varied in two dimensions, polarity (affirmative vs. negative) and truth value (true vs. false). Negative statements in Task 1 were found to be more difficult for children to verify than those in Task 2. This performance difference was used to infer the form of knowledge representation generated in verifying negative statements.     

Emotionality of encoding activity in face memory

The effects of emotionality of study tasks on face recognition were examined. Subjects made either personality decisions or self-comparisons about the people shown in a series of photographs. The personality traits judged during the encoding tasks had been selected to be either arousing or relatively nonarousing. Face recognition performance was best after an emotional nonself study task, on both immediate and delayed tests. In a companion study examining these manipulations in verbal memory, self-reference study tasks produced the best word recognition, with no difference due to the emotionality of nonself tasks. These results suggest emotionality and self-awareness have different effects on facial and verbal memory. A final study indicated that the effect of emotionality disappeared if it was added to self-reference. As regards self-reference differences in face and verbal memory, this series of experiments seems to rule out an emotionality confounding. It was concluded that self-images are less effective mnemonic aids than the propositional self-concept.     

The Effect of Clear Evaluation Criteria on Sex Bias in Judgments of Performance

Previous research indicates that the work of women is often devalued rela- tive to that of men. Two experiments tested the hypothesis that such sex bias appears when judges follow ambiguous guidelines or criteria in making evalua- tions, but not when they tollow clear evaluation guidelines. In each experiment, male and female undergraduates evaluated a performance that was attributed to either a man or woman (an intellectual test performance in Experiment I; an artistic craft object in Experiment 11). Subjects followed either clear, explicit evaluation criteria or vague, ambiguous criteria. As predicted, female subjects Lyaluated the "female's" performance less favorably than the "male's" only when. criteria were vague. In contast, male subjects showed little evidence of sex bias, regardless of the criteria they followed. Discussion centers upon: (1) possible cognitive processes underlying the observed effects of clear criteria; and (2) potential practical applications designed to alleviate sex bias in naturalistic settings.     

The influence of psychoticism and extraversion on classical eyelid conditioning using a paraorbital shock UCS

An experiment is described in which the effects of Psychoticism and Extraversion on classical eyelid conditioning were examined using a balanced design involving two levels of paraorbital shock intensity and two levels of response threshold. Questionnaire measures of Anxiety and Impulsivity were also analysed together with subjective ratings of the UCS. Results were broadly consistent with Eysenck's personality theory in that subjects scoring high on Psychoticism demonstrated lower levels of conditioning.     

An electronic cine camera system for the automatic collection and analysis of high-speed movement of unrestrained animals

A system is decribed that collects visual data using a solid-state photodiode image sensor at rates of up to 600 frames/sec in a binary format suitable for image-analysis techniques. Of particular interest is the system’s ability to analyze high-speed movement of animals without prior modification of the subject (e.g., attachment of lamps or reflectors to the subject).     

Learned helplessness in groups

Group learned helplessness is demonstrated in Experiment I. Groups of 2 tried to turn off noise by their joint action. In the solvable group (S), noise offset was contingent on their sequence of button pushing. In the yoked, unsolvable group (U), noise offset was independent of all sequences of button pushes they produced. In a practice group (O). subjects practiced coordinated sequences of button pushes with their partners, but heard no noise. Later, all 3 groups were tested in pairs in a shuttlebox which required coordinated joint responding to turn off noise. The unsolvable group escaped more poorly than the other 2 groups, paralleling helplessness effects with individuals. Experiment 2 and 3 found no transfer from individual helplessness training to group testing and no transfer from group helplessness training to individual testing. We suggest that the same mechanism, the expectation of response ineffectiveness, may mediate both individual and group learned helplessness.     

Children's strategies for controlling affective responses to aversive social experience

It was hypothesized that one mechanism of self-control that children develop is the strategic capacity to select the experiences they encounter. This hypothesis led to the prediction that children would deal with certain aversive social experiences by seeking out or taking advantage of opportunities for nurturant experiences. Young children were exposed to an aversive social experience in which they received less nurturance than a peer, a positive experience in which they received more nurturance, or a neutral experience in which nurturance was equal. Subsequently, an opportunity was provided for children to control the length of time they watched a highly nurturant television program. As predicted, boys experiencing an aversive social encounter increased the length of time they exposed themselves to the nurturant television show, and their level of reduced positive affect was related to how long they watched the nurturant content, further supporting the interpretation that they did so in response to their own affective state. Girls did not adopt the strategy of self-exposure to nurturant television but did appear to engage in self-distraction during the aversive social experience. Despite the apparent use of control strategies, there was no indication that these strategies were effective for the amelioration of reduced positive affect resulting from the aversive social experience. Discussion focuses on the sex differences observed in the adoption of strategic behavior and factors contributing to the ineffectiveness of the control strategies. A general model is proposed for personal and environmental factors requisite for the selection, employment, and effectiveness of strategies to control experiences and their affective consequences.