Chapter Nine - Serotonin and aggression

Abstract

Aggression is observed in practically all animal species, including humans. Such evolutionary conservation underscores the importance of this behavior for animals’ fitness and survival. Animals fight to defend territory, acquire food, compete for mates, and to protect their offspring. However, despite decades of research, our knowledge of neurobiological underpinnings of aggressive behavior is still far from complete. Serotonergic system has been most consistently linked to both adaptive and pathological forms of this behavior. For a long time, a prevailing hypothesis was that serotonin exerts inhibitory effect on aggression. However, ample evidence has shown that such a view may be overly simplistic and that no one-to-one relationship is likely to exist between the serotonin and aggressive behavior. In this chapter, we review the complex interplay between this iconic neurotransmitter and aggression.