Children consider the probability of random success when evaluating knowledge

To infer what others know, we must consider under what epistemic states their actions were both rational and probable. We test whether preschoolers can compare the probability of different actions (and outcomes) under different epistemic states—and use this to evaluate what others know. Specifically, four- to six-year-olds (n=90) were asked to help evaluate an agent’s knowledge state by asking the agent to complete either an “undiagnostic” task (where success was assured), or a “diagnostic task” (where the probability of random success was low). By age six, children understood that the “diagnostic” task would more likely reveal the agent’s knowledge state; four- and five-year-olds had no reliable preference, although children in all age groups understood that the “diagnostic” task was harder. These results suggest that, by the end of preschool, children understand how agents’ epistemic states and environment jointly determine success—considering whether agents’ actions imply knowledge, or just luck.

Willpower With and Without Effort

Most authors who discuss willpower assume that everyone knows what it is, but our assumptions differ to such an extent that we talk past each other. We agree that willpower is the psychological function that resists temptations—variously known as impulses, addictions, or bad habits; that it operates simultaneously with temptations, without prior commitment; and that use of it is limited by its cost, commonly called effort, as well as by the person's skill at executive functioning. However, accounts are usually not clear about how motivation functions during the application of willpower, or how motivation is related to effort. Some accounts depict willpower as the perceiving or formation of motivational contingencies that outweigh the temptation, and some depict it as a continuous use of mechanisms that interfere with re-weighing the temptation. Some others now suggest that impulse control can bypass motivation altogether, although they refer to this route as habit rather than willpower. It is argued here that willpower should be recognized as either or both of two distinct functions, which can be called resolve and suppression. Resolve is based on interpretation of a current choice as a test case for a broader set of future choices, which puts at stake more than the outcome of the current choice. Suppression is inhibiting valuation of (modulating) and/or keeping attention from (filtering) immediate alternatives to a current intention. Perception of current choices as test cases for broader outcomes may result in reliable preference for these outcomes, which is experienced as an effortless habit-- a successful result of resolve, not an alternative method of self-control. Some possible brain imaging correlates are reviewed.

Redemptive Stories and Those Who Tell Them are Preferred in the U.S.

The present studies examined the common, but untested, theoretical assumption that those in the United States prefer negative past experiences, such as trauma, to be redeemed, to be resolved in some positive or growth-promoting fashion. Narratives of six types of traumatic events that were rated by U.S adults (n = 1872) across six samples and two studies. Confirming pre-registered hypotheses, there was a reliable preference for stories that were redeemed compared to stories that ended negatively, as well as for the narrators of redemptive stories, who were judged as likable and to have desirable personality traits. There was no support for the hypothesis that redemptive stories would be viewed as more common than non-redemptive stories, or that the relation between story type and preference would be mediated by Belief in a Just World. Implications include the compulsory nature of storying trauma and potential risks of these cultural expectations.

Redemptive Stories and Those Who Tell Them are Preferred in the U.S

The present studies examined the common, but untested, theoretical assumption that those in the United States prefer negative past experiences, such as trauma, to be redeemed, to be resolved in some positive or growth-promoting fashion. Narratives of six types of traumatic events were rated by U.S adults (n = 1872) across six samples and two studies. Confirming pre-registered hypotheses, there was a reliable preference for stories that were redeemed compared to stories that ended negatively, as well as for the narrators of redemptive stories, who were judged as likable and to have desirable personality traits. There was no support for the hypothesis that redemptive stories would be viewed as more common than non-redemptive stories, or that the relation between story type and preference would be mediated by Belief in a Just World. Implications include the compulsory nature of storying trauma and potential risks of these cultural expectations.

Licking microstructure and hedonic changes after flavour preference learning in rats

Pairing a neutral flavour conditioned stimulus (CS) with a nutrient reward will create a learned preference for that CS. Prior studies suggest that this is accompanied by an increase in the hedonic value of the CS, although the reliability of this effect is yet to be fully established. Here, flavour CS+s were mixed with either 16% sucrose or maltodextrin (with control CS-s mixed with 2% solutions of the same carbohydrate). While a reliable preference for the CS+ was seen in every case, and there was a learned increase in lick cluster size when all conditions were considered together, this difference was significant in only one experimental condition considered alone. A meta-analysis of these results and similar published licking microstructure analysis studies found that the Cohen’s dav effect size for changes in licking microstructure after flavour preference learning was 0.16. This is far smaller than the effect sizes reported when assessing learned hedonic changes in flavour preference based on other test or training methods. Although this confirms that flavour preference learning produces hedonic changes in the cue flavours, the analysis of licking microstructure with training based on voluntary consumption of CS and unconditioned stimulus (US) compounds may be an insensitive means of assessing such effects.

Estimating Spatial Preferences from Votes and Text

We introduce a model that extends the standard vote choice model to encompass text. In our model, votes and speech are generated from a common set of underlying preference parameters. We estimate the parameters with a sparse Gaussian copula factor model that estimates the number of latent dimensions, is robust to outliers, and accounts for zero inflation in the data. To illustrate its workings, we apply our estimator to roll call votes and floor speech from recent sessions of the US Senate. We uncover two stable dimensions: one ideological and the other reflecting to Senators’ leadership roles. We then show how the method can leverage common speech in order to impute missing data, recovering reliable preference estimates for rank-and-file Senators given only leadership votes.

Graphic vs. Text-Only Résumés: Effects of Design Elements on Simulated Employment Decisions

Résumés sometimes contain graphical elements, and the use of such “graphical résumés” may be increasing. The purpose of this study was to compare the effect of including different types of graphical elements in a résumé on the most important outcome measure from the perspective of the applicant – the probability of a positive selection decision by the evaluator. There was a reliable preference for a textual résumé when participants asked which design they thought would be most effective. However, there was no reliable effect of résumé design on evaluator’s decisions about the applicant whose qualifications were represented.

Flashy or Functional

Résumés sometimes contain graphical elements, and the use of such “graphical résumés” may be increasing. The purpose of this study was to compare the effect of including different types of graphical elements in a résumé on the most important outcome measure from the perspective of the applicant – the probability of a positive selection decision by the evaluator. There was a reliable preference for a textual résumé when participants asked which design they thought would be most effective. However, there was no reliable effect of résumé design on evaluator’s decisions about the applicant whose qualifications were represented.

Cholecystokinin conditions flavor preferences in rats

The present study investigated whether cholecystokinin (CCK), an intestinal hormone that is a putative satiety agent, can condition flavor preference in rats. In experiment 1 food-deprived rats were trained to consume two different-flavored saccharin solutions in separate one-bottle tests. One flavor (the CS+) was paired with intraperitoneal injections of CCK octapeptide (0.125-4 micrograms/kg); the other flavor was paired with intraperitoneal injections of saline. Flavor preferences were then assessed in subsequent two-bottle choice tests. The 0.125 and 0.25 micrograms/kg doses failed to suppress CS+ intake or produce flavor preferences. CCK at 0.5 micrograms/kg did not reliably suppress CS+ intake in the one-bottle tests but produced a reliable preference for the CS+ in the two-bottle tests; percent CS+ intakes ranged from 50 to 62% in the four preference tests. At 1 microgram/kg, CCK suppressed CS+ intake and produced a marginal preference for the CS+. The 2 micrograms/kg dose suppressed CS+ intake but failed to condition a CS+ preference. The 4 micrograms/kg dose of CCK produced a potent suppression of CS+ intake and a strong aversion to that flavor. The preference conditioning effect of CCK at 0.5 microgram/kg was replicated in a second experiment using flavored Polycose solutions. The finding that low doses of CCK condition flavor preferences in rats is compatible with the hypothesis that endogenous CCK can mediate satiety and further suggests a role for CCK in learned food preferences. The aversion conditioned by the highest dose of CCK does not detract from this interpretation, since food, if consumed in excess, can also have aversive consequences.

Distilled Water and Tap Water as Factors in Taste Preference Experimentation

Albino rats were permitted to drink either distilled water or tap water from two bottles. Animals with prior experience with distilled water in the home cage showed a consistent preference for distilled water which increased over test sessions; Ss having prior experience with tap water did not show statistically reliable preference behavior. Amount of water deprivation during the test session and length of test session were not significant variables. It was concluded that previous results showing a preference for tap water reflect the operation of several variables including prior experience, but the present experiment casts doubt on interpretations, suggesting that tap water is in some general way more palatable or that tap water and distilled water may be equated when interpreting experiments on taste preference.