The psychophysics of sugar concentration discrimination and contrast evaluation in bumblebees

The capacity to discriminate between choice options is crucial for a decision-maker to avoid unprofitable options. The physical properties of rewards are presumed to be represented on context-dependent, nonlinear cognitive scales that may systematically influence reward expectation and thus choice behavior. In this study, we investigated the discrimination performance of free-flying bumblebee workers (Bombus impatiens) in a choice between sucrose solutions with different concentrations. We conducted two-alternative free choice experiments on two B. impatiens colonies containing some electronically tagged bumblebees foraging at an array of computer-automated artificial flowers that recorded individual choices. We mimicked natural foraging conditions by allowing uncertainty in the probability of reward delivery while maintaining certainty in reward concentration. We used a Bayesian approach to fit psychometric functions, relating the strength of preference for the higher concentration option to the relative intensity of the presented stimuli. Psychometric analysis was performed on visitation data from individually marked bumblebees and pooled data from unmarked individuals. Bumblebees preferred the more concentrated sugar solutions at high stimulus intensities and showed no preference at low stimulus intensities. The obtained psychometric function is consistent with reward evaluation based on perceived concentration contrast between choices. We found no evidence that bumblebees reduce reward expectations upon experiencing non-rewarded visits. We compare psychometric function parameters between the bumblebee B. impatiens and the flower bat Glossophaga commissarisi and discuss the relevance of psychophysics for pollinator-exerted selection pressures on plants.     

On the myth and the reality of the temporal validity degradation of general mental ability test scores

Claims of changes in the validity coefficients associated with general mental ability (GMA) tests due to the passage of time (i.e., temporal validity degradation) have been the focus of an on-going debate in applied psychology. To evaluate whether and, if so, under what conditions this degradation may occur, we integrate evidence from multiple sub-disciplines of psychology. The temporal stability of construct validity is considered in light of the evidence regarding the differential stability of g and the invariance of measurement properties of GMA tests over the adult life-span. The temporal stability of criterion-related validity is considered in light of evidence from long-term predictive validity studies in educational and occupational realms. The evidence gained from this broad-ranging review suggests that temporal degradation of the construct- and criterion-related validity of ability test scores may not be as ubiquitous as some have previously concluded. Rather, it appears that both construct and criterion-related validity coefficients are reasonably robust over time and that any apparent degradation of criterion-related validity coefficients has more to do with changes in the determinants of task performance and changes in the nature of the criterion domain rather temporal degradation per se (i.e., the age of the test scores). A key exception to the conclusion that temporal validity degradation is more myth than reality concerns decision validity. Although the evidence is sparse, it is likely that the utility of a given GMA test score for making diagnostic decisions about an individual deteriorates over time. Importantly, we also note several areas in need of additional and more rigorous research before strong conclusions can be supported.     

Asthma severity, child security, and child internalizing: using story stem techniques to assess the meaning children give to family and disease-specific events

Children with persistent asthma are at increased risk for mental health problems. Although mechanisms of effect are not yet known, it may be that children are less trusting of the family as a source of support and security when they have more severe asthma. This study tested whether asthma severity is related to children's perceptions of insecurity in the family, and whether insecurity is in turn associated with child adjustment. Children (N = 168; mean age = 8 years) completed story stems pertaining to routine family events (e.g., mealtimes) and ambiguous but potentially threatening asthma events such as tightness in the chest. Responses were evaluated for the extent to which appraisals portrayed the family as responding in cohesive, security-provoking ways. Asthma severity was assessed by both objective lung function testing and primary caregiver report. Caregivers reported child symptomatology. Beyond medication adherence, caregiver education, and child age and gender, greater asthma severity predicted more internalizing and externalizing symptoms. Greater asthma severity, assessed using spirometry (but not parent report), was related to less secure child narratives of the family, which in turn related to more child internalizing symptoms. Results suggest that asthma can take a considerable toll on children's feelings of security and mental health. Furthermore, given the difficulty in assessing young children's perceptions, this study helps demonstrate the potential of story stem techniques in assessing children's appraisals of illness threat and management in the family.     

Hangover sensitivity after controlled alcohol administration as predictor of post-college drinking

Predicting continued problematic levels of drinking after the early 20's could help with early identification of persons at risk. This study investigated whether hangover insensitivity could predict postcollege drinking and problems beyond the variance due to drinking patterns. In a preliminary study, 134 college seniors from a laboratory study of hangover (Time 1) were contacted and assessed 1-4 years (M = 2.3) later (Time 2). Hangover severity was studied after controlled alcohol administration to a specific dose while controlling sleep and environmental influences. Hangover severity at Time 1 was used to predict Time 2 drinking volume and problems while controlling for relevant demographics and Time 1 drinking volume. Hangover insensitivity at Time 1 tended to predict a clinical level of alcohol problems with a large statistical effect size. Hangover sensitivity also correlated positively with sensitivity to alcohol intoxication. Hangover severity did not predict future drinking volume. Hangover insensitivity correlates with insensitivity to intoxication and might predict more serious alcohol problems in the future, suggesting that a future larger study is warranted. Hangover insensitivity could result from physiological factors underlying low sensitivity to alcohol or risk for alcoholism.     

Recovering faces from memory: the distracting influence of external facial features

Recognition memory for unfamiliar faces is facilitated when contextual cues (e.g., head pose, background environment, hair and clothing) are consistent between study and test. By contrast, inconsistencies in external features, especially hair, promote errors in unfamiliar face-matching tasks. For the construction of facial composites, as carried out by witnesses and victims of crime, the role of external features (hair, ears, and neck) is less clear, although research does suggest their involvement. Here, over three experiments, we investigate the impact of external features for recovering facial memories using a modern, recognition-based composite system, EvoFIT. Participant-constructors inspected an unfamiliar target face and, one day later, repeatedly selected items from arrays of whole faces, with "breeding," to "evolve" a composite with EvoFIT; further participants (evaluators) named the resulting composites. In Experiment 1, the important internal-features (eyes, brows, nose, and mouth) were constructed more identifiably when the visual presence of external features was decreased by Gaussian blur during construction: higher blur yielded more identifiable internal-features. In Experiment 2, increasing the visible extent of external features (to match the target's) in the presented face-arrays also improved internal-features quality, although less so than when external features were masked throughout construction. Experiment 3 demonstrated that masking external-features promoted substantially more identifiable images than using the previous method of blurring external-features. Overall, the research indicates that external features are a distractive rather than a beneficial cue for face construction; the results also provide a much better method to construct composites, one that should dramatically increase identification of offenders.     

Subjective Wellbeing in a Southwestern Province in China

Differences in subjective wellbeing were examined among 3,641 men and women in Yunnan, China. Using an urban Chinese sample, Appleton and Song in World Dev 36:2325–2340, (2008) reported that SWB was positively correlated with income, reporting good health, being married, female, and a Communist Party member. The current work examines how well these findings hold in the non-coastal province of Yunnan, by gender, and by urban/rural status.     

Conducting behavioral research on Amazon’s Mechanical Turk

Amazon’s Mechanical Turk is an online labor market where requesters post jobs and workers choose which jobs to do for pay. The central purpose of this article is to demonstrate how to use this Web site for conducting behavioral research and to lower the barrier to entry for researchers who could benefit from this platform. We describe general techniques that apply to a variety of types of research and experiments across disciplines. We begin by discussing some of the advantages of doing experiments on Mechanical Turk, such as easy access to a large, stable, and diverse subject pool, the low cost of doing experiments, and faster iteration between developing theory and executing experiments. While other methods of conducting behavioral research may be comparable to or even better than Mechanical Turk on one or more of the axes outlined above, we will show that when taken as a whole Mechanical Turk can be a useful tool for many researchers. We will discuss how the behavior of workers compares with that of experts and laboratory subjects. Then we will illustrate the mechanics of putting a task on Mechanical Turk, including recruiting subjects, executing the task, and reviewing the work that was submitted. We also provide solutions to common problems that a researcher might face when executing their research on this platform, including techniques for conducting synchronous experiments, methods for ensuring high-quality work, how to keep data private, and how to maintain code security.     

Consideration of preference shifts due to relative attribute variability

This study examined whether, and if so by what mechanism, changes in relative attribute variability can elicit a decoy effect. We argue and demonstrate that when only the relative variability of the attribute values in the choice set are manipulated (i.e., a frequency-only manipulation), decoy effects are observed consistent with predictions made by the Context-Dependent Weighting hypothesis as formulated by Huber et al. [Huber, J., Payne, J.W., & Puto, C. (1982). Adding asymmetrically dominated alternatives: Violations of regularity and the similarity hypothesis. Journal of Consumer Research, 10, 31–44.]. On the surface, our results appear to contravene earlier refutations of the Context-Dependent Weighting model. However, additional results from explicit tests of the purported casual mechanism (i.e., context-dependent attribute weight changes) suggest that decision-makers’ perceived importance of dimensions did not shift in response to our manipulation, making the Loss Aversion model a more viable explanation. Finally, results from a written protocol analysis suggest that many decision-makers were unaware, or at least unable to accurately verbalize, the influence of the context. Most decision-makers purported that they had made choices on the basis of their a priori beliefs about the relative importance of attributes despite the fact that there was clear evidence of context effects. Overall, our results underscore the importance of gathering multiple types of evidence for preference shifts in order to fully understand the mechanisms underlying decision-making.     

Motives, involvements, and leadership among black college students

Thematic Apperceptive measures of achievement, affiliation, and power motives, together with consensual judges’ ratings for several clusters of attitudes, beliefs, and actions, and objective data on office-holding were obtained from thirty-eight Black undergraduate university students Overall, need for Power was related to holding office, being rated as influential, and participating in the Black Repertory Theatre. Among Northern-reared Blacks, need for Power related to ratings of activity in the extramural Black community and distrust of the System, among Southern-reared Blacks, need for Power and need for Achievement related to ratings of Pragmatism.