Chronic passive exposure to aggression escalates aggressiveness of rat observers

Abstract

Previous studies have documented that exposure to aggression increases aggressiveness of human witnesses. However, the question of whether passive exposure to aggression can exclusively cause a risk of aggressive inclination for observers through a learning process, rather than mimicry effect, has not been readily addressed in the clinical literature. This study aimed to investigate this question by using a simple animal model to test the behavioral effect of chronic passive exposure to aggression. Our results indicate that observer rats that had been passively exposed to aggression for 10 min per day for 23 consecutive days exhibited more aggressive behavior than controls or those groups undergoing a single exposure to passive aggression. Furthermore, aggression levels in the group of 23-day chronic exposure to aggression lasted 16 days after the recovery from exposure to aggression. These data suggest that the development of aggression in this model occurred through a learning process because only chronic exposure to aggression resulted in this behavioral outcome in the long run.

Neurochemical correlates of accumbal dopamine D2 and amygdaloid 5-HT1B receptor densities on observational learning of aggression

“…For example, individuals who have witnessed community and family violence in childhood tend to show aggressive and other externalizing behaviors (Guerra, Huesmann, Tolan, Van Acker, & Eron, 1995; Holmes, 2013), child abuse (Widom, 1989), positive attitudes toward aggression (Guerra, Huesmann, & Spindler, 2003; Su, Mrug, & Windle, 2010), and aggressive fantasies (Su et al, 2010). These behavioral effects of witnessing violence, also known as “passive exposure to aggression,” have been also found in animal studies; fish and rodents show aggressive tendencies following repeatedly observing fights between conspecifics (Clotfelter & Paolino, 2003; Feldker et al, 2006; Suzuki & Lucas, 2010; Welch & Welch, 1971). Therefore, it is reasonable to suggest that chronic passive exposure to aggression is a risk factor for observers’ aggressiveness.…”

Stress and neurobiology of coping styles

“…Данное уве-личение наблюдается и у «победителя», и у «проигравшего» самца . Только выше эти показатели у животного, которое на-блюдало, но не принимало участие в аг-рессивном столкновении (Suzuki, 2010) . Социальный стресс приводит к сниже-нию деятельности иммунной системы у проигравшей особи (увеличение про-воспалительных факторов (Il-1β, TNF-α, GM-CSF) в голубом пятне (LC)) .…”

L’intervention en contexte de cyberintimidation : les pratiques des enseignants

“…Par ailleurs, puisque les agresseurs peuvent cacher leur identité (Dehue et al, 2008), certaines victimes d'intimidation traditionnelle ou de cyberintimidation peuvent être à leur tour tentées de recourir, de façon anonyme, à la cyberintimidation pour se venger de leur agresseur (König, Gollwitzer, & Steffgen, 2010;Vandebosch & van Cleemput, 2008;Walrave & Heirman, 2011). Des auteurs mentionnent aussi que les témoins de situation d'intimidation en ligne sont également plus à risque de devenir agresseurs, soit par l'apprentissage de comportements observés, mais surtout par crainte d'être associés à la victime et de subir le même sort (Conway & McCord, 2002;Suzuki & Lucas, 2010). De plus, selon Jones, Manstead et Livingstone (2011), ces jeunes s'identifiant à un groupe agresseur pourraient voir leurs comportements guidés par la volonté du groupe plutôt que leur volonté personnelle, diminuant ainsi leurs sentiments de honte et de responsabilité à l'égard du tort causé à la victime.…”