* Tone of voice * Eye contact * Facial expression * Posture * Proximity * Gestures Early warning signs

* Increased activity (pacing, for example) * Threatening language * Sexist or racist taunts or depersonalising language * Change in volume of voice, shouting or very quiet * Repeated requests or demands * Clenched fists * Pointing with finger * Invasion of personal space De-escalation

* Assess the potential aggressor’s emotional state * Identify triggering factors * Maintain verbal interaction * Offer problem-solving Triggers for aggression

* Intensification of aversive stimuli such as pain or heat * Being made to wait while in pain * Disinhibition due to drugs or alcohol * Perception that there is no alternative to violence * Social cues: peer group behaviour, pressure of peer group values (avoiding loss of face), examples on TV * Life changes, new stresses (family changes, loss of job) * Interpretation of perceived normal or reasonable behaviour as unusual or unacceptable

* Frustration at obstructed wishes * Provocation or goading from third parties * Hostile environment - heat, light, noise, squalor. Does fencing in football fans make them behave worse?

* Nature of the task itself - confronting anti-social behaviour * Authority figures who present uncaring or dismissive appearance * Aggressive body posture or tone of voice, even if unintentional Consequences of inaction

* Absenteeism * Reduced performance * Low morale * High staff turnover * Increased accident rates * Raised insurance premiums