'Scared Straight' prison-visit programmes keep at-risk teens out of crime.

The intuitive idea behind Scared Straight is that exposing at-risk youth to the harsh reality of prison — via confrontational visits with inmates — will frighten them onto the straight path. The approach spread widely, aided by dramatic documentaries.

A Cochrane systematic review of randomized trials (Petrosino et al., 2013) reached a stark conclusion: the programmes not only failed to prevent crime, they increased it, with participating youth more likely to offend than controls who received no intervention. The likely reasons include glamorising defiance and labelling. This is a powerful case where a plausible, popular intervention does real harm — and why good intentions are no substitute for randomized evidence. The claim is refuted.