Horizon - How Violent Are You

Michael Portillo investigates what makes ordinary people commit extreme acts of violence, in the final Horizon of the series, and explores the fine line between control and aggression.

Michael looks at the environmental and psychological factors that can cause an individual to snap and to lose their self-control. He explores a much darker side of people's nature and asks if anyone can be driven to deliberately kill. In a thought-provoking and sometimes uncomfortable journey, Michael discovers that each of us could be inherently more violent than we think.

Michael learns what it's like to inflict pain as he takes part in the Tinku, an annual violence ritual in the Bolivian Andes. To find out if violence is addictive he meets an ex-football hooligan, who lived for his Saturday fights, and a former child soldier from war-torn Sudan, who tells a harrowing story of brainwashing, torture and regret.

In a personal challenge, Michael is pushed to his limits in an extreme sleep-deprivation test that pits him against two crying babies. After 36 hours without
sleep, he spends a pressurised day working in a professional kitchen as Professor Jane Ireland tries to find out if Michael's passive personality can be broken down to unearth a violent core.

Most surprisingly of all, he meets with Professor Peter Smith to observe one of the most violent groups in society, a group biologically incapable of controlling their aggressive instincts – ordinary three-year-olds. Michael learns how socialisation and learned experiences change the make-up of the brain and help us to control our behaviour as we age.

But what does it take for ordinary people to inflict pain in everyday situations? In a fascinating psychological study, Michael watches a replication of one of the most controversial studies in history, the Milgram study. Will participants be willing to administer a seemingly lethal electric shock to someone they think is an innocent bystander?