Male–male combats in a polymorphic lizard: residency and size,but not color,affect fighting rules and contest outcome

Theoretical models predict that the outcome of dyadic agonistic encounters between males is influenced by resource‐holding potential, resource value, and intrinsic aggressiveness of contestants. Moreover, in territorial disputes residents enjoy a further obvious competitive advantage from the residency itself, owing to the intimate familiarity with their territory. Costs of physical combats are, however, dramatically high in many instances. Thus, signals reliably reflecting fighting ability of the opponents could easily evolve in order to reduce these costs. For example, variation in color morph in polymorphic species has been associated with dominance in several case studies. In this study, we staged asymmetric resident‐intruder encounters in males of the common wall lizard Podarcis muralis, a species showing three discrete morphs (white, yellow, and red) to investigate the effects of asymmetries in color morph, residency, and size between contestants on the outcome of territorial contests. We collected aggression data by presenting each resident male with three intruders of different color morph, in three consecutive tests conducted in different days, and videotaping their interactions. The results showed that simple rules such as residency and body size differences could determine the outcome of agonistic interactions: residents were more aggressive than intruders, and larger males were competitively superior to smaller males. However, we did not find any effect of color on male aggression or fighting success, suggesting that color polymorphism in this species is not a signal of status or fighting ability in intermale conflicts. Aggr. Behav. 35:274–283, 2009. © 2009 Wiley‐Liss, Inc.     

Personality traits and endocrine response as possible asymmetry factors of agonistic outcome in karate athletes

Individual variations of plasma levels of hormones testosterone (T) and cortisol (C), before (pre) and after (post) Kumite (real fight) and Kata (ritualized fight) were measured in male karate athletes and analyzed in relation with the agonistic outcome (i.e. winning or losing the fight) and personality trait measures. T and C increased only during Kumite contest and pre‐ and post‐competition C levels were higher in losers than winners. Losers showed higher levels of harm avoidance and anxiety as well as lower level of novelty seeking than winners. Importantly, novelty seeking negatively correlates with pre C and the higher the level of risk assessment, emotionality and insecurity indexes the higher the pre C level. In conclusion, personality traits might be an important factor asymmetry between athletes influencing both the probability of winning or losing an agonistic interaction and the different anticipatory endocrine response to the incipient fight. Aggr. Behav. 35:324–333, 2009. © 2009 Wiley‐Liss, Inc.     

Play behaviors of handicapped preschool children in the presence and absence of nonhandicapped peers

Sixteen minimally handicapped children and 18 nonhandicapped children were observed playing as separate classes and as a combined group on their preschool playground. Play behaviors directed toward self, toys, teachers, and peers were recorded using a time sampling procedure. Repeated measures analyses revealed that: (1) handicapped children engaged in less peer-directed and more teacher-directed behaviors than the similar chronological age but developmentally more advanced normal children; (2) a comparison between a subsample of normal and handicapped children who were approximately equivalent on developmental age suggested that the normal children only vocalized more often; (3) when integrated with the normal children, handicapped children engaged in more peer-directed and less teacher-directed behaviors than when playing in the non-integrated situation; (4) during the combined group play situation, normal children directed more behaviors to their own classmates while handicapped children directed approximately equal amounts of behavior to their own classmates and to their normal peers. These results suggest that the normal children were not negatively affected and the handicapped children were positively affected by the integrated play situation.     

Is obesity treated like a contagious disease?

The behavioral avoidance of people with obesity is well documented, but its psychological basis is poorly understood. Based upon a disease avoidance account of stigmatization, we tested whether a person with obesity triggers equivalent self-reported emotional and avoidant-based responses as a contagious disease (i.e., influenza). Two hundred and sixty-four participants rated images depicting real disease signs (i.e., person with influenza), false alarms (i.e., person with obesity), person with facial bruising (i.e., negative control), and a healthy control for induced emotion and willingness for contact along increasing levels of physical proximity. Consistent with our prediction, as the prospect for contact became more intimate, self-reported avoidance was equivalent in the influenza and obese target conditions, with both significantly exceeding reactions to the negative and healthy controls. In addition, participants reported greatest levels of disgust toward the obese and influenza target conditions. These results are consistent with an evolved predisposition to avoid individuals with disease signs. Implicit avoidance occurs even when participants know explicitly that such signs—here, obese body form—result from a noncontagious condition. Our findings provide important evidence for a disease avoidance explanation of the stigmatization of people with obesity.     

The role of contour polarity,objectness, and regularities in haptic and visual perception

Regularities like symmetry (mirror reflection) and repetition (translation) play an important role in both visual and haptic (active touch) shape perception. Altering figure-ground factors to change what is perceived as an object influences regularity detection. For vision, symmetry is usually easier to detect within one object, whereas repetition is easier to detect across two objects. For haptics, we have not found this interaction between regularity type and objectness (Cecchetto & Lawson, Journal of Experimental Psychology: Human Perception and Performance, 43, 103–125, 2017; Lawson, Ajvani, & Cecchetto, Experimental Psychology, 63, 197–214, 2016). However, our studies used repetition stimuli with mismatched concavities, convexities, and luminance, and so had mismatched contour polarities. Such stimuli may be processed differently to stimuli with matching contour polarities. We investigated this possibility. For haptics, speeded symmetry and repetition detection for novel, planar shapes was similar. Performance deteriorated strikingly if contour polarity mismatched (keeping objectness constant), whilst there was a modest disadvantage for between-2objects:facing-sides compared to within-1object:outer-sides comparisons (keeping contour polarity constant). For the same task for vision, symmetry detection was similar to haptics (strong costs for mismatched contour polarity, weaker costs for between-2objects:facing-sides comparisons), but repetition detection was very different (weak costs for mismatched contour polarity, strong benefits for between-2objects:facing-sides comparisons). Thus, objectness was less influential than contour polarity for both haptic and visual symmetry detection, and for haptic repetition detection. However, for visual repetition detection, objectness effects reversed direction (within-1object:outer-sides comparisons were harder) and were stronger than contour polarity effects. This pattern of results suggests that regularity detection reflects information extraction as well as regularity distributions in the physical world.     

Dominance interactions in young adult paper wasp (Polistes dominulus) foundresses: a playlike behavior?

The idea that insects play has often aroused skepticism. Nevertheless, the authors investigated the occurrence of a playlike behavior in young individuals of a paper wasp. Polistes dominulus foundresses hibernate in aggregations and found associative nests in the spring. In aggregations, wasps exhibit most of the rank-dependent behaviors that they will use in the nest 6 months later. In aggregations, precocious dominance interactions are performed with exaggerated frequencies, whereas aggression and trophallaxis are rare. Dominance behavior in aggregations is apparently useless, but it probably allows wasps to assess their dominance potential without any apparent reproductive competition. Surprisingly, these interactions may be best interpreted as play because dominance behavior in aggregations shares several features with mammalian play fighting.     

Retrospective revaluation as simple associative learning

Backward blocking, unovershadowing, and backward conditioned inhibition are examples of retrospective revaluation phenomena that have been suggested to involve more than simple associative learning. Models of these phenomena have thus used additional concepts, for example, appealing to attentional effects or more elaborate learning mechanisms. The author shows that a suitable representation of stimuli, paired with a careful analysis of the discriminations faced by animals, leads to an account of these and other phenomena in terms of a simple elemental model of associative learning, with essentially the same learning mechanism as the R. A. Rescorla and A. R. Wagner (1972) model. The author concludes with a discussion of some implications for theories of learning.     

Solidarity across group lines: Secondary transfer effect of intergroup contact,perceived moral distance,and collective action

We tested, in three studies, whether the generalization of contact effects from primary to secondary outgroups—the secondary transfer effect (STE)—occurs for collective action. The results supported a serial mediation model: contact with immigrants by advantaged group members (Italians: Study 1, N = 146, 121 females, M_age = 28.31 years; Study 3, N = 406, 239 females, M_age = 36.35; British people, Study 2, N = 160, 113 females, M_age = 32.31) was associated with lower perceived moral distance toward primary outgroups, which in turn was associated with more positive attitudes and greater collective action intentions toward primary outgroups, and lower perceived moral distance toward secondary outgroups. Lower perceived moral distance toward secondary outgroups and stronger collective action intentions toward the primary outgroup were associated with higher collective action intentions toward secondary outgroups (results were inconsistent for attitudes). We discuss the findings with a focus on how a consideration of perceived moral distance extends current theorizing, and the relevance of generalized prejudice for the STE.