What do the hands externalize in simple arithmetic?

In 4 experiments, the authors examined the use of the hands in simple arithmetic tasks. Experiments 1 and 2 demonstrated that pointing increases both accuracy and speed in counting arrays of items, whether those items are identical or distinctive. Experiment 3 demonstrated that individuals tend to nod their heads when not allowed to point and that nodding is associated with greater accuracy, suggesting that pointing is functional for reasons other than simply providing additional visual information. Experiment 4 examined changes in speech when adding arrays of digits, depending on whether participants were allowed to use their hands to manipulate the tokens on which the digits were presented. Taken together, the results of these experiments are consistent with recent research suggesting that gesture can serve cognitive functions and that the hands can support the binding of representational elements to their functional roles by providing phase markers for cyclic cognitive processes.     

A beautiful day in the neighborhood: What factors determine the generation effect for simple multiplication problems?

In four experiments, we examined the generation effect for the free recall of simple multiplication answers. Large-product-size problems showed a consistent generation-effect advantage over small-product-size problems, except when each answer was generated twice, via two different sets of operands (Experiment 2). Also, measures of problem-solution time and strategy use accounted for the large-product-size advantage. Across experiments, however, small-product-size problems (but not large-product-size problems) showed considerable variation in the size of their generation effect. We discovered that solving small-product-size problems via direct memory retrieval increased the episodic recall probability of other problems that were near neighbors to the generated answer, and we attribute this result to a spreading activation mechanism in semantic memory. A measure of neighbor activations, combined with RT to solve each problem, accounted for 51% of the observed generation-effect variance.     

What causes scale errors in children?

A recent article by DeLoache et al. has documented an intriguing phenomenon in the development of action planning in young children. When children act on toy replicas of larger objects they make scale errors that are consistent with the full-sized object. Although the actions selected are inappropriate, their execution accurately takes into account the true size of the target. This phenomenon permits tests of the predictions of the perception-action and planning-control models of vision for action.     

Dunning–Kruger effects in reasoning: Theoretical implications of the failure to recognize incompetence

The Dunning–Kruger effect refers to the observation that the incompetent are often ill-suited to recognize their incompetence. Here we investigated potential Dunning–Kruger effects in high-level reasoning and, in particular, focused on the relative effectiveness of metacognitive monitoring among particularly biased reasoners. Participants who made the greatest numbers of errors on the cognitive reflection test (CRT) overestimated their performance on this test by a factor of more than 3. Overestimation decreased as CRT performance increased, and those who scored particularly high underestimated their performance. Evidence for this type of systematic miscalibration was also found on a self-report measure of analytic-thinking disposition. Namely, genuinely nonanalytic participants (on the basis of CRT performance) overreported their “need for cognition” (NC), indicating that they were dispositionally analytic when their objective performance indicated otherwise. Furthermore, estimated CRT performance was just as strong a predictor of NC as was actual CRT performance. Our results provide evidence for Dunning–Kruger effects both in estimated performance on the CRT and in self-reported analytic-thinking disposition. These findings indicate that part of the reason why people are biased is that they are either unaware of or indifferent to their own bias.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

Do Asian elephants (Elephas maximus) apply causal reasoning to tool-use tasks?

Two experiments addressed contradictory claims about causal reasoning in elephants. In Experiment 1, 4 Asian elephants (Elephas maximus) were pretrained to remove a lid from the top of a bucket and retrieve a food reward. Subsequently, in the first 5 critical trials, when the lid was placed alongside the bucket and no longer obstructed access to the reward, each elephant continued to remove the lid before retrieving the reward. Experiment 2, which involved 11 additional elephants and variations of the original design, yielded similarly counterintuitive observations. Although the results are open to alternative interpretations, they appear more consistent with associative learning than with causal reasoning. Future applications of Fabrean methodologies (J. H. Fabre, 1915) to animal cognition are proposed.     

What causes auditory distraction?

The role of separating task-relevant from task-irrelevant aspects of the environment is typically assigned to the executive functioning of working memory. However, pervasive aspects of auditory distraction have been shown to be unrelated to working memory capacity in a range of studies of individual differences. We measured individual differences in global pattern matching and deliberate recoding of auditory sequences, and showed that, although deliberate processing was related to short-term memory performance, it did not predict the extent to which that performance was disrupted by task-irrelevant sound. Individual differences in global sequence processing were, however, positively related to the degree to which auditory distraction occurred. We argue that much auditory distraction, rather than being a negative function of working memory capacity, is in fact a positive function of the acuity of obligatory auditory processing.     

What causes alternations in dominance during binocular rivalry?

Several mechanisms have been proposed to account for perceptual alterations during binocular rivalry, including neural adaptation and neural noise. However, the importance of neural adaptation for producing perceptual alterations has been challenged in several articles (Y.-J. Kim, Grabowecky, & Suzuki, 2006; Moreno-Bote, Rinzel, & Rubin, 2007). We devised an “online” adaptation procedure to reexamine the role of adaptation in binocular rivalry. Periods of adaptation inserted into rivalry observation periods parametrically alter the dynamics of rivalry such that increased adaptation duration decreases dominance duration, which cannot be accounted for by neural noise. Analysis of the average dominance durations and their variance (coefficient of variation) provides evidence for an increasingly important role of noise in rivalry alternations as a given dominance period continues in time, consistent with recent computational models.     

Assessment of fighting ability or simple habituation: What causes young pigs (Sus scrofa) to stop fighting?

To determine how pigs assess their relative fighting ability, I observed paired contests between young pigs that were either of similar weight or of different weight. On the first day the incidence of fighting was high, but this was not affected by the size of the weight difference. Fights between pigs of different weight were shorter than those between pigs of similar weight. When the pigs were of different weight, the eventual winner bit more frequently and spent more time attacking than did the eventual loser. This difference was not apparent when the pigs were of similar weight. On the first day, winners and losers were equally likely to initiate fights. The incidence of fighting was lower on the second day, although this was unaffected by the weight difference. Losers were less likely to initiate fights on the second day, and fights were shorter than on the first day. However, for the time that they did fight, the losers fought as vigorously (based on the rate of biting) on the second day as on the first. Seventy-two hours of visual and olfactory contact before the fight had no effect on the incidence of fighting and minimal effect on its duration. I suggest a young pig cannot assess its chance of success prior to the first encounter but only during the course of the fight. This assessment is reduced by attacks from the opponent until it drops below a critical threshold, whereupon the pig stops fighting. As a result of a previous defeat, a pig will lower its assessment and will be less likely to fight or to initiate fights on subsequent encounters. It is this change in assessment rather than habituation alone that makes pigs less likely to fight as they become acquainted.     

Respect for the Dignity of People: What Does This Principle Mean in Practice?

Researchers have found that disrespectful behaviour can have a notable psychological impact on victims and observers thereof. It is not surprising, therefore, that law and all the major psychology codes of ethics acknowledge the principle of respect for the dignity of persons. The practical implications of this principle, however, are not clear. In this article we argue, with reference to the philosophical roots of the principle, that there are rules of manners in all societies that describe how people should demonstrate respect for persons. Generally, the profession cannot require psychologists to adhere to the rules of manners, not even those that demonstrate respect for persons, but it can, and does, prescribe to psychologists how they should act while they practice as psychologists. We proceed to examine the principles and standards of the Australian Psychology Society's Code of Ethics (2007) that require psychologists to demonstrate respect for persons while acting as psychologists.     

Can We Justifiably Assume the Cosmological Principle in Order to Break Model Underdetermination in Cosmology?

If cosmology is to obtain knowledge about the whole universe, it faces an underdetermination problem: Alternative space-time models are compatible with our evidence. The problem can be avoided though, if there are good reasons to adopt the Cosmological Principle (CP), because, assuming the principle, one can confine oneself to the small class of homogeneous and isotropic space-time models. The aim of this paper is to ask whether there are good reasons to adopt the Cosmological Principle in order to avoid underdetermination in cosmology. Various strategies to justify the CP are examined. For instance, arguments to the effect that the truth of the CP follows generically from a large set of initial conditions; an inference to the best explanation; and an inductive strategy are assessed. I conclude that a convincing justification of the CP has not yet been established, but this claim is contingent on a number of results that may have to be revised in the future.     

Dual processes in reasoning?

Previous results have shown that the introduction of negatives into the sentences used in a deductive problem affected behavior in a systematic way which was independent of the logical structure of the problem. In the present investigation, the subjects were asked to justify their responses when reasoning about such sentences. In accordance with previous results, the responses were dominated by the terms in the sentences regardless of whether they were negated. However, the justifications did vary when negatives were introduced in accordance with the logical consequences of the responses. The interpretation of these justifications as causes of behavior seemed implausible. It was suggested that they were rationalizations, or that there was at least some form of dual processing between behavior and conscious thought.     

What does principled versus conventional moral reasoning convey to others about the politics and psychology of the reasoner?

The well‐documented relationship between political orientation and moral reasoning has most often been interpreted in terms of the influence of level of moral development (cf. Kohlberg, 1984) upon an individual's political inclinations: those who have reached the conventional level (or stage 4) in Kohlberg's terms will as a result tend to favour the political right, whereas those who progress to the principled level (stage 5) shift their political preferences to the left. An alternative, ‘social communication’ view is that these different forms of moral reasoning are expressions of contrasting political identities, and differ in ideological content rather than developmental level. We compared the inferences that American and British students (n=211) drew about the political, moral and cognitive attributes of a target who, in response to moral dilemmas, used either stage 4A, stage 4B or stage 5 moral arguments as defined by Kohlberg. Perception of the target's political attributes varied consistently and significantly as a function of the target's moral reasoning, but there were no corresponding effects on perception of moral or cognitive attributes. The results are interpreted as supporting a social communication view of moral reasoning and its relation to political orientation, and at the same time questioning the claim that conventional (stage 4) and principled (stage 5) moral reasoning are distinct levels of socio‐cognitive development. Copyright © 1999 John Wiley & Sons, Ltd.