ao3 evaluation

• • Correlation vs. causation: Even if low serotonin and aggressive behaviour are correlated, it does not automatically prove that low serotonin causes aggressive behaviour. For example, serotonin could decrease in response to angry feelings, in which case it could be an effect of aggression rather than a cause.
• • Conflicting evidence: The exact role of serotonin in aggression is somewhat unclear, as research can be conflicting. For example, Huber et al (1997) demonstrated that injecting crayfish with serotonin made them behave more aggressively rather than less (although as an animal study these findings may not be valid when applied to humans).