Reducing probabilistic weather forecasts to the worst-case scenario: anchoring effects

Many weather forecast providers believe that forecast uncertainty in the form of the worst-case scenario would be useful for general public end users. We tested this suggestion in 4 studies using realistic weather-related decision tasks involving high winds and low temperatures. College undergraduates, given the statistical equivalent of the worst-case scenario (1 boundary of the 80% predictive interval), demonstrated biased understanding of future weather conditions compared with those given both bounds or no uncertainty information. We argue that this was due to an anchoring effect on numeric estimates, which were closer to the worst-case scenario than was warranted and increased linearly as the anchor became more extreme. In many situations tested here, anchoring in numeric estimates also extended to subsequent binary decisions, leading participants with the worst-case scenario to take action more often than did other participants. These results suggest that worst-case scenario forecasts can mislead the user. They appear to convince people that wind speeds will be higher and temperatures will be lower than what are indicated by the forecast. In addition, participants systematically "corrected" the forecast they were given. This effect was most prominent in the condition in which no uncertainty was provided, suggesting that people feel compelled to take uncertainty into account, even when it is not acknowledged by the forecast. Both the anchoring and correction biases were least evident when both bounds were provided, suggesting that balanced uncertainty leads to the best understanding of future weather conditions.     

Contextual validity and the effects of low-constraint sentence contexts on lexical decisions

Subjects made lexical decisions after reading either (a) low-constraint sentence contexts that did not predict the identity or meaning of congruous targets (e.g. “Mary went to her room to look at her XXXX”), or (b) control contexts that were randomly ordered lists of words. The crucial variable was the validity of the contextual information. When the sentence contexts were incongrous with the word targets as often as they were congruous (the “less-valid environment”), the congruous contexts had a slight inhibitory effect on decision latency relative to the baseline condition. In contrast, when the contexts were always congruous with the word targets (“valid environment”), they had a large facilitatory effect on decision latency. These results suggest that (a) the effects of congruous contexts can depend on the validity of the contexts across the entire experimental session, and (b) contextual facilitation may be due in part to sentence level processes.     

Positive and negative recency effects in retirement savings decisions

Retirement savings decisions can be influenced by the fund composition of the retirement savings plan. In 2 experiments, strong composition effects were observed, with a larger percentage of resources being invested in stock funds when more stock than bond funds were offered. Although participants changed their allocations repeatedly, the opportunity to learn did not alter the composition effects. Learning processes led to positive and negative recency effects as well, providing evidence that allocations were strongly influenced by the recent performance of the different allocation options. Two learning models were tested to explain these learning processes. The first, a local adaptation learning model, assumes that people change their behavior on the basis of recent experience, whereas the second, a reinforcement learning model, assumes that decisions are made on the basis of the totality of accumulated experience. The local adaptation model was more accurate in predicting allocation decisions, in explaining positive and negative recency effects, and in showing why composition effects are not overcome by learning.     

Market entry decisions: effects of absolute and relative confidence

In a market entry game, the number of entrants usually approaches game-theoretic equilibrium quickly, but in real-world markets business start-ups typically exceed market capacity, resulting in chronically high failure rates and suboptimal industry profits. Excessive entry has been attributed to overconfidence arising when expected payoffs depend partly on skill. In an experimental test of this hypothesis, 96 participants played 24 rounds of a market entry game, with expected payoffs dependent partly on skill on half the rounds, after their confidence was manipulated and measured. The results provide direct support for the hypothesis that high levels of confidence are largely responsible for excessive entry, and they suggest that absolute confidence, independent of interpersonal comparison, rather than confidence about one's abilities relative to others, drives excessive entry decisions when skill is involved.     

Hemispheric asymmetry in lexical decisions: the effects of grammatical class and imageability

It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.     

Multiple cognitive control effects of error likelihood and conflict

Recent work on cognitive control has suggested a variety of performance monitoring functions of the anterior cingulate cortex such as errors, conflict, error likelihood, and others. Given the variety of monitoring effects, a corresponding variety of control effects on behavior might be expected. This paper explores whether conflict and error likelihood produce distinct cognitive control effects on behavior, as measured by response time. A Change signal task (Brown & Braver, Science 307:1118–1121, 2005) was modified to include conditions of likely errors due to tardy as well as premature responses in conditions with and without conflict. The results discriminate between competing hypotheses of independent versus interacting conflict and error likelihood control effects. Specifically, the results suggest that the likelihood of premature versus tardy response errors can lead to multiple distinct control effects, which are independent of cognitive control effects driven by response conflict. As a whole, the results point to the existence of multiple distinct cognitive control mechanisms and challenge existing models of cognitive control that incorporate only a single control signal.     

Framing effects in decisions with completely and incompletely described alternatives

Earlier research has shown that a variety of judgments depend upon how key sources of information are framed. Framing effects have been extended to include relative evaluations of stimuli with complete and incomplete information. The present study was designed to see if these effects are predictive of discrete choices and to isolate the locus of the framing effect. In Experiment 1 subjects were asked to indicate whether they would take each of a series of gambles described by payoff and probability information or by only one of these values. As predicted, subjects in the positive condition were more apt than subjects in the negative condition to take gambles when probability information was included, but not when it was missing. Subjects in Experiment 2 chose between gambles with complete and incomplete information. Consistent with the earlier findings, subjects in the positive condition were less apt than subjects in the negative condition to choose the gamble with missing probability information. Experiment 3 replicated the results of Experiment 2 while eliminating various psychophysical factors as causes of the framing effect. The way stimuli are framed appears to affect their subjective scale values and this determines both how they are responded to in an absolute sense and how they are compared to other stimuli.     

Boundary effects of vague risk information on taxpayer decisions

In compliance decisions, the decision maker usually has only vague or ambiguous knowledge of the probability of being caught and the outcome (amount of penalty). An experiment is reported which extends work on effects of probability ambiguity by manipulating outcome ambiguity as well. When outcomes were limited to a bounded range and probabilities ranged between their natural boundaries [0, 1] in experimental tax decisions, symmetrical boundary effects were found in which vague estimates for both the probability and outcome dimensions caused vagueness aversion (and higher compliance) when the vague estimate was near the more favorable lower boundary of either dimension and vagueness seeking (and lower compliance) when the vague estimate was near the less favorable upper boundary. Probability and outcome vagueness effects were found to be independent of the vagueness of the other dimension, and vagueness effects were not systematically related to the level of the other dimension.The results suggest that a common cognitive process mediates the impact of vagueness on both dimensions. This may be a vagueness-adjustment process in which vague estimates are adjusted toward the middle of the bounded range, or a vagueness-preference process in which vague outcomes, and vague probabilities as well, are evaluated based on utility considerations, as though probability were a tangible commodity. For increasing compliance, the results suggest that risk information should be disseminated only when risks of punishment are relatively high. When risks are low, random enforcement techniques that enhance vagueness become more effective.     

Membership experiences in gender-sexuality alliances (GSAs) predict increased hope and attenuate the effects of victimization

We examined whether students' experiences in their Gender-Sexuality Alliances (GSAs) over the school year predicted positive development or thriving in the form of higher relative levels of hope at the end of the school year and whether GSA experiences also promoted resilience by attenuating the link between victimization and lower relative levels of hope among 366 student members of 38 GSAs (M_age = 15.53 years; 85% sexual minority; 55% cisgender female; 72% White). Our findings indicated that, when considered one at a time, students' perceptions of receiving more social-emotional support, receiving more information and resources, and undertaking more advocacy in their GSA throughout the school year predicted higher relative levels of hope at the end of that school year (adjusted for students' initial hope at the beginning of the year). When considering all three GSA-based experiences concurrently, receiving more information and resources in their GSA had a unique predictive association with hope and it reduced the extent to which reported experiences of victimization at school predicted diminished hope at the end of the year. There was a similar, though statistically non-significant, moderating trend for advocacy.     

Sentence frame contexts and lexical decisions: Sentence-acceptability and word-relatedness effects

Many studies have explored the effects of single-word contexts on visual word recognition, and several models have been proposed to account for the results obtained. However, relatively little is known about the effects of sentence contexts. In the experiment reported, the contexts consisted of sentences with the final word deleted, and subjects made word-nonword (lexical) decisions on target strings of letters. Norms were collected to determine the most common completion for each sentence frame. The experiment yielded three main findings: (1) Lexical decisions were fastest for words that were the most common completions; (2) among words not given as completions in the norming procedure, decisions were faster for words related to the most common completions than for words unrelated to the most common completions; t3t also among words that were not produced as completions, decisions were faster for words that formed acceptable completions than for words that did not. These relatedness and sentence-acceptability effects were independent, so that the relatedness effect held even when the target words formed anomalous sentence completions. In order to account for these results, a model combining two types of processes is required. In the model described, schematic knowledge (Rumelhart & Ortony, 1977) operates upon a semantic network to activate particular nodes, and this activation spreads to related concepts as in the Collins and Loftus (1975) model.     

Examining the impact of error estimation on the effects of self-controlled feedback

Two experiments were conducted that examined the motivational and informational perspectives concerning learning advantages from self-controlled practice. Three groups were tasked with learning a novel skill; self-controlled (SC), yoked traditional (YT), and yoked with error estimation required during the acquisition phase (YE). Results from the delayed learning measures showed the YE group performed better than the SC and YT groups, for Expt. 1. A similar pattern emerged for Expt. 2, albeit, this was not significant. While there were no motivation differences across the groups in either experiment, a strong correlation in Expt. 2 was shown between error estimation capabilities, which were best for the YE group, and learning. These combined results suggest that informational processes contribute more to the self-controlled feedback learning advantage, relative to motivational contributions.     

Semantic and phonological context effects in speech error repair

When speakers repair speech errors, they plan the repair in the context of an abandoned word (the error) that is usually similar in meaning or form. Two picture-naming experiments tested whether the error's lexical representations influence repair planning. Context pictures were sometimes replaced with target pictures; the picture names were related in meaning or form or were unrelated. The authors measured target picture-naming latencies separately for trials in which the context name was interrupted or completed. Interrupted trials showed semantic interference and phonological facilitation, whereas completed trials showed semantic facilitation and phonological interference. Thus, errors influence repair production. The authors explain the polarity of these effects in terms of the literature on context effects in word production.     

Factor analysis; some effects of chance error

Ignorance concerning the standard error of individual factor loadings and their differences has been a major obstacle to the proper interpretation of factorial results. The effects of three types of experimental error (selection of variables, selection of subjects and selection of scores) are here reported. In order to handle the errors of rotation systematically, it has been necessary to introduce a new semi-analytical criterion for the attainment of simple structure. Variability in results which may theoretically be eliminated is discussed under the heading of non-essential error.     

The effects of prior expectations and outcome knowledge on polygraph examiners' decisions

The present study deals with the question of whether judgments made by experts working in familiar contexts are affected by prior expectations and beliefs. Two experiments in which prior expectations were manipulated were designed to determine whether and to what extent polygraph examiners are affected by their prior expectations when analyzing and interpreting polygraph charts. Prior expectations affected the examiners' judgments when the polygraph charts did not include clear indications of guilt or innocence, but when the objective physiological evidence included strong indications which clearly contradicted the examiner's expectations, judgments were not affected by these expectations. Theoretical and practical implications of these results are discussed.     

Motivated prediction of future feelings: effects of negative mood and mood orientation on affective forecasts

This article examines the role of motivational factors in affective forecasting. The primary hypothesis was that people predict positive emotional reactions to future events when they are motivated to enhance their current feelings. Three experiments manipulated participants' moods (negative vs. neutral) and orientation toward their moods (reflective vs. ruminative) and then assessed the positivity of their affective predictions for future events. As hypothesized, when participants adopted a reflective orientation, and thus should have been motivated to engage in mood-regulation processes, they predicted more positive feelings in the negative than in the neutral mood condition. This pattern of mood-incongruent affective prediction was not exhibited when participants adopted a ruminative orientation. Additionally, within the negative mood condition, generating affective forecasts had a more positive emotional impact on reflectors than on ruminators. The findings suggest that affective predictions are sometimes driven by mood-regulatory motives.     

Differential effects of main error correction versus secondary error correction on motor pattern of running

The aim of this study was to gain a better understanding of how the run pattern varies as a consequence to main error correction versus secondary error correction. Twenty-two university students were randomly assigned to one of two training-conditions: ‘main error’ (ME) and ‘secondary error’ (SE) correction. The rear-foot strike at touchdown was hypothesized as the ‘main error’, whereas an incorrect shoulder position (i.e., behind the base of support) as the ‘secondary error’. In order to evaluate any changes in run pattern at the foot touchdown instant, the ankle, knee and hip joint angles, the height of toe and heel (with respect to the ground), and the horizontal distance from the heel to the projected center of mass on the ground were measured. After the training-intervention, the ME group showed a significant improvement in the run pattern at the foot touchdown instant in all kinematic parameters, whereas no significant changes were found in the SE group. The results support the hypothesis that the main error can have a greater influence on the movement patterns than a secondary error. Furthermore, the findings highlight that a correct diagnosis and the correction of the ‘main error’ are fundamental for greater run pattern improvement.