Late for work in Manhattan, you push the crosswalk button and curse silently at the slowness of the signal change. You finally get a green light, cross the street, arrive at the office, get in the elevator and hit the close door (>|<) button to speed things along. Getting out on your target floor, you find that hurrying has you a bit hot under the collar, so you reach for the thermostat to turn up the air conditioning.

Each of these seemingly disconnected everyday buttons you pressed may have something in common: it is quite possible that none of them did a thing to influence the world around you. Any perceived impact may simply have been imaginary, a placebo effect giving you the illusion of control.

In the early 2000s, New York City transportation officials finally admitted what many had suspected: the majority of crosswalk buttons in the city are completely disconnected from the traffic light system. Thousands of these initially worked to request a signal change but most no longer do anything, even if their signage suggests otherwise.

Naturally, a number of street art projects have popped up around the humorous futility of pedestrians pressing placebo buttons:

Crosswalk buttons were originally introduced to NYC during the 1960s. At the time, there was less congestion and it made sense to leave green lights on for major thoroughfares until cross traffic came along … or until a pedestrian wanting to cross the street pushed a button.

Today, a combination of carefully orchestrated automation and higher traffic has made most of these buttons obsolete. Citywide, there are around 100 crosswalk buttons that still work in NYC but close to 1,000 more that do nothing at all. So why not take them down? Removing the remaining nonfunctional buttons would cost the city millions, a potential waste of already limited funds for civic infrastructure.

Like push-to-cross buttons on streets, push-to-close buttons in elevators vary in their efficacy. Some work, others do not, and many are keyed for access only by police, firemen or maintenance workers.

There are other tricks that may work in some cases to speed your lift along, including: holding down your target floor button or sweeping your arm across the door sensor so the system thinks someone exited.

Perhaps one of the most overtly insidious examples of a placebo device is the fake office thermostat. Some offer complete or partial control, but others have absolutely no effect on a building’s HVAC system.

Sometimes the culprit is a real estate leasing company, duping its corporate renters. In other cases, a company boss or senior managers may not want ordinary employees fiddling with the temperature dial.

Estimates vary wildly depending on who you ask, but anywhere from a few percent to the majority of office thermostats may be fake. According to an HVAC technician interviewed by the Wall Street Journal, 90% of office thermostats are non-functional.

In the same article, a senior commercial real estate executive in New York City explains that some buildings go so far as to install white noise generators to simulate the hum of a fan. When users go to turn the dial on the office thermostat, they hear noise and assume it is working. In other cases, the dials may be hooked into the system, but only have a limited range of influence, nudging the temperature slightly.

If this all sounds unfair or even infuriating, there is another side to the story. In 1975, psychologist Ellen Langer (now a professor at Harvard) was a graduate student at Yale. She wrote a paper on the “illusion of control,” but framed the effect in a positive light.

“Feeling you have control over your world is a desirable state,” Langer explained in an interview with the BBC. “Doing something is better than doing nothing, so people believe. And when you go to press the button your attention is on the activity at hand. If I’m just standing at the corner I may not even see the light change, or I might only catch the last part of the change, in which case I could put myself in danger.”

Placebo buttons at stoplights are by no means limited to the United States. In places like Hong Kong and London, some buttons work only at certain times of day (if at all). Meanwhile in Hildesheim, Germany a group of interaction design students have developed another way to keep pedestrians busy while they wait, replacing a pointless placebo with an entertaining activity. When the walk light is red, people waiting across the street from one another can share a short game of Pong, playing on screens attached to corner traffic light posts.

At the end of the day, placebo buttons do little harm and may well do a bit of good. If nothing else, they give people something to do while waiting for street lights or elevators, perhaps even a creating brief connection between strangers forced to spend time together either way.