Naive theory and transfer of learning: When less is more and more is less

In this research, we examine how young children perform induction in the domain of biology. According to the essentialist view, even young children have a priori knowledge that some predictors of biological properties are central, whereas others are peripheral. According to the flexible-learning view, the roles of predictors are not fixed, and young children flexibly learn the predictive value of each predictor. In the experiment reported, 4- to 5-year-olds and 11- to 12-year-old preadolescents were taught the predictive values of features that were (by the essentialist account) either central or peripheral for predicting the biological properties of animals. Retention of the learned predictors was then tested immediately after learning, 1 h after leaning, and 2.5–3.5 months later. The results indicate that 2.5–3.5 months after learning, young children retained learned predictors well regardless of their putative centrality, whereas preadolescents were likely to retain and recall only central, but not peripheral, predictors.     

Probabilistic cue combination: less is more

Learning about the structure of the world requires learning probabilistic relationships: rules in which cues do not predict outcomes with certainty. However, in some cases, the ability to track probabilistic relationships is a handicap, leading adults to perform non‐normatively in prediction tasks. For example, in the dilution effect, predictions made from the combination of two cues of different strengths are less accurate than those made from the stronger cue alone. Here we show that dilution is an adult problem; 11‐month‐old infants combine strong and weak predictors normatively. These results extend and add support for the less is more hypothesis: limited cognitive resources can lead children to represent probabilistic information differently from adults, and this difference in representation can have important downstream consequences for prediction.     

Smelling more or less: Investigating the olfactory experience of the domestic dog

The performance of tracking dogs and drug-, disease-, and explosives-detection dogs is a testament to trained dogs’ olfactory acuity. The olfactory experience of an untrained dog, by contrast, has not been well documented. In the current research we begin to remedy that by testing untrained pet dogs’ olfactory perception of quantity. While previous research found that dogs could discriminate visible quantities of more or less food (Prato-Previde, Marshall-Pescini, & Valsecchi, 2008), our results find that, by contrast, companion dogs do not reliably discriminate quantities when the food can be smelled but not seen. Sixty-one percent of dogs (39 of 64), given a choice between closed plates with one and five morsels of food, approached plates with the larger quantity: not significantly more than approached plates with the lesser quantity (binomial, p = .169). We did find that during dogs’ initial investigation of both food amounts, subjects gave more attention to the plate containing the larger quantity (binomial, p < 0.001). In a second condition, we replicated, with closed plates, Prato-Previde et al.’s (2008) finding that owner interest in a plate holding a lesser quantity of food reliably leads dogs to approach that plate (binomial, p < 0.001). Though research has demonstrated dogs’ preference for a larger amount of food ( Ward & Smuts, 2007), in a third condition testing the effect of adding a strong odor to a visibly larger food quantity, we found that the addition of odor often reversed that preference (44/69 dogs; p < .03). Finally, we consider the methodological implications of this work on future dog cognition studies.     

Idiosyncratic matching and choice: When less is more

In three studies, reliance on “goodness-of-fit” criteria exerted an influence on assessments of pay-TV packages that challenged normative standards relating to the principle of dominance. Studies 1 and 2 showed that the addition of one or more non-favored channels to a package of favored ones resulted in lower consumer interest, and the subtraction of one or more non-favored channels from a mixed package resulted in greater consumer interest, even when the relevant offering price remained unchanged. Study 3 demonstrated the specific relevance of perceived idiosyncrasy to this phenomenon. Thus, participants responded more positively to a given price reduction for relinquishing a channel they did not like when they believed that their preference ordering was idiosyncratic rather than one shared by their peers. These findings, buttressed by additional data collection to rule out some alternative interpretations and permit within-subject as well as between-subject comparisons, extend the theoretical and practical implications of previous research on the non-normative use of personal “goodness-of-fit” criteria in evaluating the attractiveness of products and programs.     

When less is more and when more is more: The mediating roles of capacity and speed in brain-behavior efficiency

An enduring enterprise of experimental psychology has been to account for individual differences in human performance. Recent advances in neuroimaging have permitted testing of hypotheses regarding the neural bases of individual differences but this burgeoning literature has been characterized by inconsistent results. We argue that careful design and analysis of neuroimaging studies is required to separate individual differences in processing capacity from individual differences in processing speed to account for these differences in the literature. We utilized task designs which permitted separation of processing capacity influences on brain-behavior relationships from those related to processing speed. In one set of studies, participants performed verbal delayed-recognition tasks during blocked and event-related fMRI scanning. The results indicated that those participants with greater working memory (WM) capacity showed greater prefrontal cortical activity, strategically capitalized on the additional processing time available in the delay period, and evinced faster WM-retrieval rates than low-capacity participants. In another study, participants performed a digit-symbol substitution task (DSST) designed to minimize WM storage capacity requirements and maximize processing speed requirements during fMRI scanning. In some prefrontal cortical (PFC) brain regions, participants with faster processing speed showed less PFC activity than slower performers while in other PFC and parietal regions they showed greater activity. Regional-causality analysis indicated that PFC exerted more influence over other brain regions for slower than for faster individuals. These results support a model of neural efficiency in which individuals differ in the extent of direct processing links between neural nodes. One benefit of direct processing links may be a surplus of resources that maximize available capacity permitting fast and accurate performance.     

When more is less: Negative exposure effects in unsupervised learning

In this article, two broad classes of models of unsupervised learning are compared: correlation tracking models, according to which learning is expected to increase monotonically with exposure to instances, and category invention models, which can accommodate specific violations of monotonicity (negative exposure effects). In two experiments, increasing the number of training instances had a negative rather than a positive effect on unsupervised learning, a clear violation of monotonicity. The results of these experiments are then compared with the predictions of two computational models, one a category invention model and the other a correlation tracking model. The category invention model was able to reproduce the qualitative pattern of results from the human data, whereas the correlation tracking model was not. Overall, these results provide strong evidence for the existence of a discrete category invention process in unsupervised learning.     

When more is less: feedback effects in perceptual category learning

Rule-based and information-integration category learning were compared under minimal and full feedback conditions. Rule-based category structures are those for which the optimal rule is verbalizable. Information-integration category structures are those for which the optimal rule is not verbalizable. With minimal feedback subjects are told whether their response was correct or incorrect, but are not informed of the correct category assignment. With full feedback subjects are informed of the correctness of their response and are also informed of the correct category assignment. An examination of the distinct neural circuits that subserve rule-based and information-integration category learning leads to the counterintuitive prediction that full feedback should facilitate rule-based learning but should also hinder information-integration learning. This prediction was supported in the experiment reported below. The implications of these results for theories of learning are discussed.     

When less is more: Consumer aversion to unused utility

A series of experiments demonstrates that consumers exhibit aversion to waste during forward-looking purchase. These experiments further reveal that such behavior is driven by distaste for unused utility, a reaction that is shown to be distinct from an aversion to squandering money. Waste aversion is especially pronounced when consumers anticipate future consequences and deprivation is salient. In addition to demonstrating robustness across consumers and marketing contexts, the results also demonstrate how waste aversion can lead to self-defeating behavior in which consumers forego desired utility. Finally, the present research demonstrates and discusses the implications of waste aversion for a variety of marketing issues, including buy-rent markets, bundling, and the fundamental distinction between goods and services.     

Reclaiming the value of assessing unconscious and subjective psychological experience

The Psychodynamic Diagnostic Manual provides a model of the individual that emphasizes the prominence of unconscious subjective experience in shaping personality and psychopathology. Yet, modern psychiatry and psychology have avoided reference to and assessment of such processes. In this article, I review evidence from the cognitive neuroscience literature that supports the relationship of unconscious subjective experience to personality and behavior. Suggestions are made for how these findings should affect clinical assessment practice and how research methodology could be employed to further evaluate and enhance current assessment practice.     

Recall accuracy and illusory memories: when more is less

In two experiments it was revealed that manipulations that increased recall of studied list items also increased false recall of theme-related, critical nonpresented words. In Experiment 1 subjects listened to a series of short word lists, each containing items associatively related to a theme, while engaging in either semantic or nonsemantic processing. On an immediate free recall test semantic processors demonstrated greater correct recall as well as more illusory memories of critical nonpresented items than nonsemantic processors. In Experiment 2, the short study lists were combined to form longer lists that were presented either blocked by theme or in a random presentation order. Retention interval was also varied as participants were tested either immediately, one week after, or three weeks after the study phase. Presenting the target items in a blocked, as opposed to random, format increased recall accuracy, but this was at the expense of a higher intrusion rate for theme-consistent items. Interestingly, the level of false memories was not affected by retention interval even though typical decrements in the recall of study items were observed over time. The results of these experiments highlight the persistence of the false memory effect, as well as pointing to several factors, primarily semantic processing, that may lead to the creation of false memories. Interpretations are offered within the theoretical frameworks of source monitoring and fuzzy trace theory.     

Suboptimal choice by dogs: when less is better than more

The less is more effect, an example of an affect heuristic, can be shown in humans when they give greater value to a set of six baseball cards in perfect condition, than to the same set of six perfect cards together with three additional cards each with some value but in fair condition. A similar effect has been reported in monkeys which will eat both grapes and cucumbers but prefer grapes, when they prefer a single grape over a single grape plus a slice of cucumber. In the present experiment, we tested the less is more effect with a nonprimate but social species, dogs. We used dogs that would eat a slice of carrot and a slice of cheese but preferred the cheese. When we then gave them a choice between a slice of cheese and a slice of cheese plus a slice of carrot, most dogs preferred the single slice of cheese. Thus, the less is more effect appears to occur in several species.     

How task experience influences students' performance expectancies: the role of certainty

The importance of performance expectancies for predicting behavior has long been highlighted in research on expectancy-value models. These models do not take into account that expectancies may vary in terms of their certainty. The study tested the following predictions: task experience leads to a higher certainty of expectancies; certainty and mean expectancies are empirically distinguishable; and expectancies held with high certainty are more accurate for predicting performance. 273 Grade 8 students reported their performance expectancy and the certainty of expectation with regard to a mathematics examination immediately before and after the examination. Actual grades on the examination were also assessed. The results supported the predictions: there was an increase in certainty between the two times of measurement; expectancies and certainty were unrelated at both times of measurement; and for students initially reporting higher certainty, the accuracy of the performance expectancy (i.e., the relation between expectancy and performance) was higher than for students reporting lower certainty. Given lower certainty, the accuracy increased after the students had experience with the examination. The data indicate that it may be useful to include certainty as an additional variable in expectancy-value models.     

The role of prior task experience in temporal misestimation

The effect of experience with a preceding task on the accuracy of predictions of duration was examined in three experiments, where two tasks comprising similar or different mental operators were performed consecutively. Results supported an anchoring account of misestimation, which states that misestimation occurs because predictions are anchored to the duration of the preceding task. Preceding performance of a longer task led to overestimation on a shorter task with similar mental operators (Experiment 1), whereas preceding performance of a shorter task comprising similar or different mental operators led to underestimation on a longer task (Experiments 1 to 3). Contrary to the planning fallacy account (Kahneman & Tversky, 1979), these findings indicate that preceding task performance is considered when predicting duration, but that using such information does not necessarily improve accuracy.     

The role of prior task experience in temporal misestimation

The effect of experience with a preceding task on the accuracy of predictions of duration was examined in three experiments, where two tasks comprising similar or different mental operators were performed consecutively. Results supported an anchoring account of misestimation, which states that misestimation occurs because predictions are anchored to the duration of the preceding task. Preceding performance of a longer task led to overestimation on a shorter task with similar mental operators (Experiment 1), whereas preceding performance of a shorter task comprising similar or different mental operators led to underestimation on a longer task (Experiments 1 to 3). Contrary to the planning fallacy account (Kahneman & Tversky, 1979), these findings indicate that preceding task performance is considered when predicting duration, but that using such information does not necessarily improve accuracy.     

Less is more: meta-analyses of sensitivity and attachment interventions in early childhood

Is early preventive intervention effective in enhancing parental sensitivity and infant attachment security, and if so, what type of intervention is most successful? Seventy studies were traced, producing 88 intervention effects on sensitivity (n = 7,636) and/or attachment (n = 1,503). Randomized interventions appeared rather effective in changing insensitive parenting (d = 0.33) and infant attachment insecurity (d = 0.20). The most effective interventions used a moderate number of sessions and a clear-cut behavioral focus in families with, as well as without, multiple problems. Interventions that were more effective in enhancing parental sensitivity were also more effective in enhancing attachment security, which supports the notion of a causal role of sensitivity in shaping attachment.     

Decisions beyond boundaries: when more information is processed faster than less

Bounded rationality models usually converge in claiming that decision time and the amount of computational steps needed to come to a decision are positively correlated. The empirical evidence for this claim is, however, equivocal. We conducted a study that tests this claim by adding and omitting information. We demonstrate that even an increase in information amount can yield a decrease in decision time if the added information increases coherence in the information set. Rather than being influenced by amount of information, decision time systematically increased with decreasing coherence. The results are discussed with reference to a parallel constraint satisfaction approach to decision making, which assumes that information integration is operated in an automatic, holistic manner.     

When less is not always more: stereotype knowledge and reasoning development

Developmental studies on heuristics and biases have reported controversial findings suggesting that children sometimes reason more logically than do adults. We addressed the controversy by testing the impact of children's knowledge of the heuristic stereotypes that are typically cued in these studies. Five-year-old preschoolers and 8-year-old children were tested with a card game version of the classic base-rate task. Problems were based on stereotypes that were familiar or unfamiliar for preschoolers. We also manipulated whether the cued stereotypical response was consistent (no-conflict problems) or inconsistent (conflict problems) with the correct analytic response that was cued in the problem. Results showed that an age-related performance decrease on the conflict problems was accompanied by an age-related performance increase on the no-conflict problems. These age effects were most pronounced for problems that adopted stereotypes that were unfamiliar for the 5-year-old preschoolers. When preschoolers were familiar with the stereotypes, their performance also started being affected. Findings support the claim that previously reported age-related performance decreases on classic reasoning tasks need to be attributed to the increased need to deal with tempting heuristics and not to a decrease in analytic thinking skills per se.     

When and how less is more: reply to Tharp and Pickering

In DeCaro et al. [DeCaro, M. S., Thomas, R. D., & Beilock, S. L. (2008). Individual differences in category learning: Sometimes less working memory capacity is better than more. Cognition, 107, 284-294] we demonstrated that sometimes less working memory (WM) has its advantages. The lower individuals’ WM, the faster they achieved success on an information-integration (II) category learning task adopted from Waldron and Ashby [Waldron, E. M., & Ashby, F. G. (2001). The effects of concurrent task interference on category learning: Evidence for multiple category learning systems. Psychonomic Bulletin & Review, 8, 168-176]. We attributed this success to the inability of lower WM individuals to employ explicit learning strategies heavily reliant on executive control. This in turn, we hypothesized, might push lower WM individuals to readily adopt procedural-based strategies thought to lead to success on the II task. Tharp and Pickering [Tharp, I. J., & Pickering, A. D. (2009). A note on DeCaro, Thomas, and Beilock (2008): Further data demonstrate complexities in the assessment of information-integration category learning. Cognition] recently questioned whether the II category learning task DeCaro et al. used really reflects procedural learning. In an effort to investigate Tharp and Pickering’s assertions with respect to individual differences in WM, we replicate and extend our previous work, in part by modeling participants’ response strategies during learning. We once again reveal that lower WM individuals demonstrate earlier II learning than their higher WM counterparts. However, we also show that low WM individuals’ initial success is not because of procedural-based responding. Instead, individuals lower in WM capacity perseverate in using simple rule-based strategies that circumvent heavy demands on WM while producing above-chance accuracy.     

Integrating novel dimensions to eliminate category exceptions: when more is less

Category learning can be characterized as a process of discovering the dimensions that represent stimuli efficiently and effectively. Categories that are overlapping when represented in 1 dimensionality may be separate in a higher dimensional cue set. The authors report 2 experiments in which participants were shown an additional cue after learning to use 2 imperfect cues. The results revealed that participants can integrate new information into their categorization cue set. The authors discovered wide individual differences, however, with many participants favoring simpler, but less accurate, cue sets. Some participants demonstrated the ability to discard information previously used when new, more accurate information was introduced. The categorization model RASHNL (J. K. Kruschke & M. K. Johansen, 1999) gave qualitatively accurate fits of the data.