Refining the blank line-up procedure: How should we instruct eyewitnesses?

Presenting a blank line-up—containing only fillers—to witnesses prior to showing a real line-up might be useful for screening out those who pick from the blank line-up as unreliable witnesses. We show that the effectiveness of this procedure varies depending on instructions given to witnesses. Participants (N = 462) viewed a simulated crime and attempted to identify the perpetrator from a line-up approximately 1 week later. Rejecting a blank line-up was associated with greater identification accuracy and greater diagnosticity of suspect identifications, but only when witnesses were instructed prior to the blank line-up that they would view a series of line-ups; the procedure was ineffective for screening when witnesses were advised they would view two line-ups or received no instruction. These results highlight the importance of instructions used in the blank line-up procedure, and the need for better understanding of how to interpret choosing patterns in this paradigm.     

Measuring the time course of selection during visual search

In visual search tasks, observers can guide their attention towards items in the visual field that share features with the target item. In this series of studies, we examined the time course of guidance toward a subset of items that have the same color as the target item. Landolt Cs were placed on 16 colored disks. Fifteen distractor Cs had gaps facing up or down while one target C had a gap facing left or right. Observers searched for the target C and reported which side contained the gap as quickly as possible. In the absence of other information, observers must search at random through the Cs. However, during the trial, the disks changed colors. Twelve disks were now of one color and four disks were of another color. Observers knew that the target C would always be in the smaller color set. The experimental question was how quickly observers could guide their attention to the smaller color set. Results indicate that observers could not make instantaneous use of color information to guide the search, even when they knew which two colors would be appearing on every trial. In each study, it took participants 200–300 ms to fully utilize the color information once presented. Control studies replicated the finding with more saturated colors and with colored C stimuli (rather than Cs on colored disks). We conclude that segregation of a display by color for the purposes of guidance takes 200–300 ms to fully develop.     

Relationship between sexual activity and intraspecific fighting in male mice

Significantly more male mice having cohabited and mated with intact females subsequently displayed intraspecific fighting behavior after castration than males having cohabited with noncycling (ovariectomized) females. Also, intact males that failed to achieve a criterion for aggression during three screening tests subsequently showed a marked increase in fighting after having had copulatory experience relative to males that lived with ovariectomized females. Lastly, spontaneously aggressive males copulated more frequently than nonfighters.     

Within-Family Effects of Smoking during Pregnancy on ADHD: the Importance of Phenotype

We sought to test within- and between- family associations of smoking during pregnancy (SDP) and attention deficit-hyperactivity disorder (ADHD) symptoms using a structured interview based on the conventional Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) symptoms and the Strengths and Weaknesses of ADHD-Symptoms and Normal-Behavior (SWAN) scale, which is a population based measure that grew out of the notion that an ADHD diagnosis exists on the extreme end of a continuum of normative behaviors and includes both above- and below- average performance on attention and activity. We used a sibling-comparison approach in a sample of 173 families including siblings aged 7–16 years (52% male) drawn from the state of Missouri, USA, wherein mothers smoked during one pregnancy but not the other. There was a within-family effect of smoking during pregnancy on SWAN hyperactivity/impulsivity and SWAN total ADHD behaviors. The associations between SDP and DSM-IV-based ADHD symptom dimensions as well as SWAN inattention were explained by familial confounds. These findings suggest that SDP exerts a potentially causal effect on increased ADHD hyperactive/impulsive behaviors and that this SDP effect is best captured when hyperactivity/impulsivity is assessed more normatively across the population, rather than specifically assessing problematic behaviors via DSM symptoms. Thus, any potentially causal effect of SDP on ADHD symptom dimensions may be restricted to hyperactive/impulsive behaviors rather than inattention, and normative, non-DSM-IV based behavioral measures may provide a more sensitive test of mechanisms of SDP-ADHD symptom associations, particularly in non-clinical samples.     

SAINTLY SACRIFICE: THE TRADITIONAL TRANSMISSION OF MORAL ELEVATION

Abstract This paper combines the social psychology concept of moral elevation with the evolutionary concept of traditions as descendant‐leaving strategies to produce a new explanation of the role of saints in Christianity. Moral elevation refers to the ability of prosocial acts to inspire people to engage in their own acts of charity and kindness. When morally elevating stories and visual depictions become traditional by being passed from one generation to the next, they can produce prosocial behavior advantageous to survival and reproduction among many generations of descendants. Traditions that increase the number of descendants in future generations can be seen as descendant‐leaving strategies. Stories and visual depictions of the sacrifices of saints appear to be designed to produce states of moral elevation, and they have been transmitted from one generation to the next for many centuries. We propose that this ability of sacrificing saints to inspire future generations to engage in prosocial acts has contributed to the continuation and spread of Christianity.     

Expectancies of infant-feeding methods among mothers in three ethnic groups

Abstract

The psychometric characteristics and construct validity of an inventory of expectancy statements about breast- and formula-feeding were assessed to refine a measure of the predictors of breastfeeding initiation and maintenance. Respondents were a tri-ethnic sample of mostly lower income mothers within two days after delivery. Ninety-six expectancy items reflecting eight hypothesized domains in expectancies of breastfeeding (BF) and formula-feeding(FF) were submitted to maximum likelihood factor analysis. Four factors were determined: “Benefits of BF,” “Relative Advantages of FF,” “Inconveniences of FF,” and “Relative Inconveniences of BF.” All factors were significantly related to actual BF of the new infant in the expected directions using unweighted factor scores in a multiple logistic regression analysis. Predicted BF closely matched actual BF for all ethnicities combined with a total error rate for misclassification of only 14%. This match was high for Anglo- and Black-American mothers. Each of the factors was determined to be reliably estimated by the ten most highly loaded items without an appreciable loss of internal consistency. Further research must assess expectancies prior to delivery in order to assess their predictiveness of behavior. and must further clarify the meaning of the expectancy factors to facilitate intervention.     

Children's responses to cognitive challenge and links to self-reported rumination

We tested the hypothesis that less effective responses during a cognitive challenge would relate to higher levels of self-reported rumination in children. The sample was 100 children (55 boys, 45 girls), aged 7 to 14 years. A portion (n=65) was at high risk for depression due to having a parent with a childhood-onset mood disorder, and 35 were a low-risk comparison group. Using an impossible puzzle task, we assessed children's responses following failure across several domains: emotions (expressed anger, sadness, and negative self-statements), performance (being off-task, the time to solve subsequent puzzles, and the number solved), and physiology (heart rate, respiratory sinus arrhythmia). Results indicated that making negative self-blaming statements during the solvable puzzles and taking more time to solve the puzzles were associated with higher levels of self-reported rumination. Our findings advance the understanding of potential correlates of children's tendency to ruminate and may have implications for children's performance on cognitive tasks.     

On the source and scope of priming effects of masked stimuli on endogenous shifts of spatial attention

Unconscious stimuli can influence participants’ motor behavior as well as more complex mental processes. Previous cue-priming experiments demonstrated that masked cues can modulate endogenous shifts of spatial attention as measured by choice reaction time tasks. Here, we applied a signal detection task with masked luminance targets to determine the source and the scope of effects of masked stimuli. Target-detection performance was modulated by prime-cue congruency, indicating that prime-cue congruency modulates signal enhancement at early levels of target processing. These effects, however, were only found when the prime was perceptually similar to the cue indicting that primes influence early target processing in an indirect way by facilitating cue processing. Together with previous research we conclude that masked stimuli can modulate perceptual and post-central levels of processing. Findings mark a new limit of the effects of unconscious stimuli which seem to have a smaller scope than conscious stimuli.