Egg incubation effects generate positive correlations between size,speed and learning ability in young lizards

Previous studies have suggested that body size and locomotor performance are targets of Darwinian selection in reptiles. However, much of the variation in these traits may derive from phenotypically plastic responses to incubation temperature, rather than from underlying genetic variation. Intriguingly, incubation temperature may also influence cognitive traits such as learning ability. Therefore, we might expect correlations between a reptile’s size, locomotor speed and learning ability either due to selection on all of these traits or due to environmental effects during egg incubation. In the present study, we incubated lizard eggs (Scincidae: Bassiana duperreyi) under ‘hot’ and ‘cold’ thermal regimes and then assessed differences in hatchling body size, running speed and learning ability. We measured learning ability using a Y-maze and a food reward. We found high correlations between size, speed and learning ability, using two different metrics to quantify learning (time to solution, and directness of route), and showed that environmental effects (incubation temperature) cause these correlations. If widespread, such correlations challenge any simple interpretation of fitness advantages due to body size or speed within a population; for example, survivors may be larger and faster than nonsurvivors because of differences in learning ability, not because of their size or speed.     

How dogs scan familiar and inverted faces: an eye movement study

Faces play an important role in communication and identity recognition in social animals. Domestic dogs often respond to human facial cues, but their face processing is weakly understood. In this study, facial inversion effect (deficits in face processing when the image is turned upside down) and responses to personal familiarity were tested using eye movement tracking. A total of 23 pet dogs and eight kennel dogs were compared to establish the effects of life experiences on their scanning behavior. All dogs preferred conspecific faces and showed great interest in the eye area, suggesting that they perceived images representing faces. Dogs fixated at the upright faces as long as the inverted faces, but the eye area of upright faces gathered longer total duration and greater relative fixation duration than the eye area of inverted stimuli, regardless of the species (dog or human) shown in the image. Personally, familiar faces and eyes attracted more fixations than the strange ones, suggesting that dogs are likely to recognize conspecific and human faces in photographs. The results imply that face scanning in dogs is guided not only by the physical properties of images, but also by semantic factors. In conclusion, in a free-viewing task, dogs seem to target their fixations at naturally salient and familiar items. Facial images were generally more attractive for pet dogs than kennel dogs, but living environment did not affect conspecific preference or inversion and familiarity responses, suggesting that the basic mechanisms of face processing in dogs could be hardwired or might develop under limited exposure.     

Global self-esteem and method effects: Competing factor structures,longitudinal invariance,and response styles in adolescents

The Rosenberg Self-Esteem Scale (RSES) is a widely used measure for assessing self-esteem, but its factor structure is debated. Our goals were to compare 10 alternative models for the RSES and to quantify and predict the method effects. This sample involves two waves (N =2,513 9th-grade and 2,370 10th-grade students) from five waves of a school-based longitudinal study. The RSES was administered in each wave. The global self-esteem factor with two latent method factors yielded the best fit to the data. The global factor explained a large amount of the common variance (61% and 46%); however, a relatively large proportion of the common variance was attributed to the negative method factor (34 % and 41%), and a small proportion of the common variance was explained by the positive method factor (5% and 13%). We conceptualized the method effect as a response style and found that being a girl and having a higher number of depressive symptoms were associated with both low self-esteem and negative response style, as measured by the negative method factor. Our study supported the one global self-esteem construct and quantified the method effects in adolescents.     

Audiovisual presentation of video-recorded stimuli at a high frame rate

A method for creating and presenting video-recorded synchronized audiovisual stimuli at a high frame rate—which would be highly useful for psychophysical studies on, for example, just-noticeable differences and gating—is presented. Methods for accomplishing this include recording audio and video separately using an exact synchronization signal, editing the recordings and finding exact synchronization points, and presenting the synchronized audiovisual stimuli with a desired frame rate on a cathode ray tube display using MATLAB and Psychophysics Toolbox 3. The methods from an empirical gating study (Moradi, Lidestam, & Rönnberg, Frontiers in Psychology 4:359, 2013) are presented as an example of the implementation of playback at 120 fps.     

A unique visual rhythm does not pop out

We investigated attentional demands in visual rhythm perception of periodically moving stimuli using a visual search paradigm. A dynamic search display consisted of vertically “bouncing dots” with regular rhythms. The search target was defined by a unique visual rhythm (i.e., a shorter or longer period) among rhythmic distractors with identical periods. We found that search efficiency for a faster or a slower periodically moving target decreased as the number of distractors increased, although searching for a faster target was about one second faster than searching for a slower target. We conclude that perception of a visual rhythm defined by a unique period is not a “pop-out” process, but a serial one that demands considerable attention.     

Ethical Issues in Doctoral Supervision: The Perspectives of PhD Students in the Natural and Behavioral Sciences

Our aim was to identify the ethical issues faced by students in the behavioral and natural sciences during their doctoral programmes. The participants were 28 PhD students who were interviewed about their doctoral study and supervision experiences. We identified a total of 102 ethical issues compromising the principles of nonmaleficence, beneficence, autonomy, justice, or fidelity. There were some differences in emphases, with the students in the behavioral sciences displaying a broader range of ethical compromises than the students in the natural sciences. Ethical problems emerged in the individual supervisor–student relationships, but often problems involving the scholarly community appeared in the background.     

Prejudice‐reduction in Culturally Mixed Classrooms: The Development and Assessment of a Theory‐driven Intervention Among Majority and Minority Youth in Finland

The aim of this field experiment was to develop and assess an intervention promoting positive intergroup relations in culturally diverse schools. The intervention was based on extended contact and social learning and utilized behavioural journalism as its method. Intervention effects were assessed on out‐group attitudes, perceived importance of future contact, perceived peer norms and intergroup anxiety among ethnic majority (N = 583) and minority (N = 214) youth in grades 7–9 in Finnish secondary schools (total N_experimental = 388; total N_control = 409). As a result of the intervention, both groups showed a tendency to perceive future intergroup contact as more important, and this effect was most notable for younger participants and girls. Prototypicality of in‐group and out‐group peer models contributed positively to intervention effects. However, unexpectedly, the intervention also increased experiences of intergroup anxiety among the oldest participants. The results are discussed taking into account the developmental stage of the youth studied. Besides critically assessing the effectiveness of the intervention, recommendations for improving theory‐driven prejudice‐reduction and for the development of future interventions in culturally diverse contexts are given. Copyright © 2013 John Wiley & Sons, Ltd.     

Paternal involvement elevates trajectories of life satisfaction during transition to parenthood

This study explored the role of fathers' involvement for life satisfaction changes among 598 cohabitating couples before and after childbirth using data from the German Socio-Economic Panel (GSOEP). We included longitudinal data and reports from both parents on their time spent on housework and childcare and their life satisfaction. Piecewise latent growth models showed that fathers' relative involvement trajectories for housework and childcare (amount of time men spent compared to their partners) were positively correlated. Fathers' relative involvement was perceived as supportive for mothers' childcare. In families where fathers were more involved, life satisfaction trajectories were much steeper; both parents had elevated levels around birth and returned to their baseline levels compared to families with less-involved fathers. Fathers who were less involved did not increase in life satisfaction at birth and decreased below their baseline levels within the third year post-birth.