Early Monday morning in Paris, businesswoman and reality star Kim Kardashian was robbed at gunpoint then left locked and tied in her bathroom. The five assailants, still at large, escaped with more than $10 million worth of jewelry. According to The Guardian the robbers were able to gain entry from the concierge of Kardashian’s building by disguising themselves as police, then handcuffing and ordering him to show them her apartment, before forcing themselves inside.

Luckily, Kardashian walked away from the ordeal. A spokesman has said she is “badly shaken but physically unharmed.” But how is it possible that the closely guarded Kardashian could ever be in this situation? The truth is that it most likely comes down to a psychological hack: The concierge reacted like any of us would when encountered by a seemingly real squad of police. He respected the uniform.

Police uniforms have been shown to consistently influence the perception of the officer wearing it. Attached with the uniform is a perception of power and authority, and in turn studies show that when people interact with an officer in uniform versus an officer in street clothes they are more likely to curb illegal behavior. This perception of status through a superficial aspect of appearance starts in childhood and continues into adulthood.

A study published in The Journal of Psychology demonstrates just how powerful a uniform can be. When researchers showed groups of female subjects portraits of police officers, they identified the ones in uniform as the most competent, reliable, intelligent, and helpful. That each photograph was still technically a police officer didn’t matter.

Kardashian’s concierge likely reacted in the same, very normal way. When a police officer knocks on the door you usually answer, regardless of who is in your building.

Photos via Getty Images / Pascal Le Segretain