Speaker 1: Welcome to brain Stuff, a production of iHeartRadio. Hey Brainstuff.
Speaker 1: Lauren Vogebomb here with another classic episode from the Vault.
Speaker 1: In this one, we take a look at the history
Speaker 1: of a common, everyday object so ubiquitous that you probably
Speaker 1: don't think much about it, but that was nonetheless designed
Speaker 1: to stand out. We're looking at the traffic stop sign.
Speaker 1: Hey brain Stuff. I'm Lauren vogelbamb and today's question is
Speaker 1: why are stop signs read? Why not green or purple?
Speaker 1: Why not mango tango or tickle me pink. In the
Speaker 1: early days of motor vehicles, the rules of the road
Speaker 1: were let's say, there were really more what you'd call
Speaker 1: guidelines than actual rules. Believe it or not, the first
Speaker 1: stop signs in America were not put in place until
Speaker 1: nineteen fifteen. According to historical estimates by the Federal Highway Administration,
Speaker 1: in nineteen fifteen, there were already almost two point five
Speaker 1: million cars driving on US roads when when those much
Speaker 1: needed first stop signs finally did show up. It happened
Speaker 1: in the motor capital of Detroit, Michigan. And they were
Speaker 1: not the red octagons that we know and love today,
Speaker 1: but white squares with black letters. Now traffic sign codes
Speaker 1: throughout the twentieth century have recommended several different variations on
Speaker 1: the basic design. For example, in nineteen thirty five, the
Speaker 1: United States got its first official manual on Uniform Traffic
Speaker 1: Controlled Devices, which said stop signs should be a yellow
Speaker 1: octagon with black or red lettering. It wasn't until the
Speaker 1: nineteen fifty four revision of this nineteen forty eight edition
Speaker 1: of the manual that the red octagon with white letters
Speaker 1: became the law of the land. According to that document,
Speaker 1: the red color is consistent with the accepted use of
Speaker 1: a red light as a stop signal and of the
Speaker 1: color red as a special warning of danger. Furthermore, they
Speaker 1: explained that the original decision to use yellow instead of
Speaker 1: red was because red pigments were more likely to fade
Speaker 1: over time with exposure to the elements. However, by the
Speaker 1: nineteen fifties, the state of California had solved the problem
Speaker 1: by using porcelain enamel to protect their precious red signs,
Speaker 1: and higher durability red paints were becoming more widely available,
Speaker 1: and like that, red became the new yellow. But there's
Speaker 1: a question that goes deeper than uniform traffic signaling protocol.
Speaker 1: Why red is there any reason to think a red
Speaker 1: stop sign would work better than any other color at
Speaker 1: getting drivers to stop zooming straight through intersections at eighty
Speaker 1: eight miles per hour. One fairly obvious answer is that
Speaker 1: red is not as likely to blend in with the
Speaker 1: landscape as some other colors. This explains why the highway
Speaker 1: administration has repeatedly rejected our proposal for a green and
Speaker 1: brown camouflage patterned stop sign. Another important point is that,
Speaker 1: like the aforementioned manual says a red is a color
Speaker 1: we consistently use to identify warnings and peril a think
Speaker 1: about the wrong way sign and the do not enter sign.
Speaker 1: Having consistent color coding helps drivers learn to identify specific
Speaker 1: colors with specific messages. So even if you only catch
Speaker 1: the hint of a red sign out of the corner
Speaker 1: of your eye, you're more likely to react with caution
Speaker 1: the way you've been taught. There are also some behavioral
Speaker 1: research findings that might point to the inherent power of
Speaker 1: the color red to command our obedience. For example, a
Speaker 1: twenty eleven study published in Psychological Science found that male
Speaker 1: recis monkeys under test conditions were less likely to steal
Speaker 1: apple slices from human experimenters who were dressed in red.
Speaker 1: The monkeys didn't seem to care about the gender of
Speaker 1: the human experimenter and were not deterred by green or
Speaker 1: blue clothing, but a red hat and T shirt were
Speaker 1: enough to make the monkeys cautious about swiping that fruit. Now,
Speaker 1: it's important not to read too much into that result.
Speaker 1: The study was done on monkeys who could be reacting
Speaker 1: to red for all kinds of reasons, but it at
Speaker 1: least suggests the possibility that there is a primate instinct
Speaker 1: to associate red with dominance or authority, and if humans
Speaker 1: share this hypothetical primate instinct, the difference between a red
Speaker 1: stop sign and a yellow stop sign might be the
Speaker 1: difference between stop and the name of the law. And hey, hey,
Speaker 1: hey guys, it might be nice if you've came to
Speaker 1: a halt or you know, turned off your nitro boosters.
Speaker 1: Today's episode is based on a video script written by
Speaker 1: Joe McCormick for the brain Stuff YouTube channel, which is
Speaker 1: a thing that we used to have to hear more
Speaker 1: from Joe check out his podcast Stuff to Blow your Mind.
Speaker 1: Brain Stuff is production of iHeartRadio in partnership with houstuffworks
Speaker 1: dot com and it is produced by Tyler Klang. Four
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