Positive Effects of Prosocial Cartoon Viewing on Aggression Among Children: The Potential Mediating Role of Aggressive Motivation

Prosocial cartoon is characterized by helping others solve difficulties, including helping, donating, sharing, comforting, and cooperating. The current study examined whether viewing a prosocial cartoon decreases aggression immediately upon exposure and the potential mediating role of aggressive motivation. Participants involve 168 children (Mage = 5.87 years, SD = 0.41) nominated by teachers as aggressive from three Chinese kindergartens. Children in the treatment group watched a prosocial cartoon (American cartoon “Handy Manny”), while children in the control group watched a nonprosocial cartoon (Chinese cartoon “Fruity Robo”). Afterward, the Hot Sauce Task (HST) was employed to assess aggressive behavior, and Aggressive Motivation Questionnaire (AMQ) was employed to assess aggressive motivation. Results revealed that viewing a prosocial cartoon (vs. a nonprosocial cartoon) did reduce children’s aggression immediately upon exposure. Specifically, males showed less aggressive behavior than females upon prosocial cartoon exposure, while males showed more aggressive behavior than females upon nonprosocial cartoon exposure. Mediational analysis suggested that the prosocial cartoon effect on aggression was partially mediated by aggressive motivation, especially for males. Consistent with general aggression model (GAM), findings of the study indicated that short-term exposure to a prosocial cartoon decreased children’s aggression by reducing aggressive motivation.

Body coloration as a dynamic signal during intrasexual communication in a cichlid fish

Background Intrasexual competition over access to resources can lead to aggression between individuals. Because overt aggression, i.e. fights, can be costly for contestants, the communication of aggressive motivation prior to engagement in a physical fight is often mediated by conventional signals. Animals of various taxa, including fishes, display visual signals such as body coloration that can dynamically be adjusted depending on the individual’s motivation. Male individuals of the West African cichlid Pelvicachromis taeniatus express a yellow body coloration displayed during courtship but also in an intrasexual competition context. Results Within-individual variation in male yellow body coloration, as quantified with standardized digital photography and representation in a CIELab color space, was examined in a mating context by exposing males to a female and in a competitive intrasexual context, i.e. in a dyadic contest. Additionally, spectrometric reflectance measurements were taken to obtain color representations in a physiological color space based on spectral sensitivities of our model species. Exposure to females did not significantly affect male color expression. However, analysis of body coloration revealed a change in within-individual color intensity and colored area after interaction with a male competitor. In dominant males, extension of coloration was positively correlated with restrained aggression, i.e. displays, which in turn explained dominance established between the two contestants. Conclusion Body coloration in male P. taeniatus is a dynamic signal that is used in concert with display behavior in communication during intrasexual competition.

Catechol-O-Methyltransferase Gene Val158Met Polymorphism Moderates the Effect of Social Exclusion and Inclusion on Aggression in Men: Findings From a Mixed Experimental Design

Accumulating research has identified the interactive effects of catechol-O-methyltransferase (COMT) gene Val158Met polymorphism and environmental factors on aggression. However, available evidence was mainly based upon correlational design, which yields mixed findings concerning who (Val vs. Met carriers) are more affected by environmental conditions and has been challenged for the low power of analyses on gene–environment interaction. Drawing on a mixed design, we scrutinized how COMT Val158Met polymorphism (between-group variable) impacts on aggression, assessed by hostility, aggressive motivation, and aggressive behavior, under different social conditions (exclusion vs. inclusion, within-group variable) in a sample of 70 Chinese male undergraduate students. We found that both Val/Val homozygote and Met alleles carriers showed differences in the feelings of hostility and aggressive motivation under conditions of exclusion versus inclusion, but these differences were more pronounced for Met allele carriers. These findings implied that COMT Val158Met polymorphism did not respond to environmental stimuli in an all-or-none way and shed light on the importance of examining the gene–environment interaction using a mixed design.

Habitat selection and territoriality

Insects dominate virtually all terrestrial and freshwater habitats on earth. This chapter reviews insect habitat selection, focusing on the occupation and defence of mating sites. First the adaptive basis of mating systems, sex roles, and behaviors in regard to habitat are established, then site occupation and defence in territorial species is explored. Resource-holding potential and resource value are discussed for how they determine aggressive motivation, as well as how contestants seek to gauge such parameters, with particular attention to the role of convention, drawing upon exemplar studies in damselflies and butterflies that have provided a narrative between theory and empiricism. Conventional and/or plastic behaviors are also discussed in terms of the presence and certainty of contestant roles, encompassing phenomena, such as residency confusion, nasty neighbours and interloper effects. The chapter concludes by discussing future avenues, foremost among which is the opportunity to synthesize empirical data across taxa.

Acute fluoxetine differently affects aggressive display in zebrafish phenotypes

Zebrafish have been introduced as a model organism in behavioral neuroscience and biological psychiatry, increasing the breadth of findings using fish to study the neurobiology of aggression. Phenotypic differences between leopard and longfin zebrafish were exploited in order to elucidate the role of phasic serotonin in aggressive displays on this species. The present study revealed differences in aggressive display between leopard and longfin zebrafish, and a discrepant effect of acute fluoxetine in both populations. In mirror-induced aggression, leopard animals showed higher display latencies than longfin, as well as lower display duration and frequency (Experiment 1). Moreover, 2.5 mg/kg fluoxetine decreased the duration and frequency of display in longfin, but not leopard; and 5 mg/kg fluoxetine increased display frequency in leopard, but not longfin (Experiment 2). It is suggested that zebrafish from the longfin phenotype show more aggressive motivation and readiness in the mirror-induced aggression test that leopard, and that acute fluoxetine increases aggression in leopard and decreased it in longfin zebrafish.