It catches your eye every time you wait to cross a pedestrian crossing: the small black, red or green button supposed to speed up the passage of traffic lights to red. We pressed him once, then twice, hoping to finally be able to cross the street. But is this device effective, or does it simply have a placebo effect that allows us to relax in the middle of traffic? This is the question asked by korii, the business and tech vertical of Slate magazine.

Quoted by our colleagues, psychologist Ellen Langer, from Harvard, explains that this button has the sole purpose of satisfying the desire for control of pedestrians. “They have a psychological effect. Performing an action makes people feel in control of the situation, and it feels more good than suffering from it,” she said.

If all the push buttons do not have this placebo function, we are however talking about a majority: “In New York, for example, around 10% of the 1,000 buttons present near the crosswalks were in working order in 2018, d “according to the spokespersons of the municipal transport service. This is much less than in 2004, when three quarters of these buttons were functional”, specifies korii.

These placebo buttons are also found in elevators, in the form of pictograms indicating that the elevator doors could close or open more quickly… As well as in hotels! According to korii, some thermostat knobs in hotel rooms are programmed, simply to give guests an illusion of control.