1 00:00:01,840 --> 00:00:07,560 Speaker 1: Welcome to brain Stuff, a production of iHeartRadio. Hey Brainstuff. 2 00:00:07,600 --> 00:00:10,960 Speaker 1: Lauren Vogebomb here with another classic episode from the Vault. 3 00:00:11,800 --> 00:00:14,040 Speaker 1: In this one, we take a look at the history 4 00:00:14,160 --> 00:00:17,960 Speaker 1: of a common, everyday object so ubiquitous that you probably 5 00:00:18,000 --> 00:00:21,120 Speaker 1: don't think much about it, but that was nonetheless designed 6 00:00:21,160 --> 00:00:25,080 Speaker 1: to stand out. We're looking at the traffic stop sign. 7 00:00:27,320 --> 00:00:30,400 Speaker 1: Hey brain Stuff. I'm Lauren vogelbamb and today's question is 8 00:00:30,520 --> 00:00:33,760 Speaker 1: why are stop signs read? Why not green or purple? 9 00:00:33,840 --> 00:00:37,199 Speaker 1: Why not mango tango or tickle me pink. In the 10 00:00:37,240 --> 00:00:39,400 Speaker 1: early days of motor vehicles, the rules of the road 11 00:00:39,440 --> 00:00:42,000 Speaker 1: were let's say, there were really more what you'd call 12 00:00:42,200 --> 00:00:45,520 Speaker 1: guidelines than actual rules. Believe it or not, the first 13 00:00:45,520 --> 00:00:48,040 Speaker 1: stop signs in America were not put in place until 14 00:00:48,120 --> 00:00:53,120 Speaker 1: nineteen fifteen. According to historical estimates by the Federal Highway Administration, 15 00:00:53,479 --> 00:00:56,360 Speaker 1: in nineteen fifteen, there were already almost two point five 16 00:00:56,560 --> 00:01:00,720 Speaker 1: million cars driving on US roads when when those much 17 00:01:00,840 --> 00:01:03,880 Speaker 1: needed first stop signs finally did show up. It happened 18 00:01:03,920 --> 00:01:06,920 Speaker 1: in the motor capital of Detroit, Michigan. And they were 19 00:01:06,959 --> 00:01:09,199 Speaker 1: not the red octagons that we know and love today, 20 00:01:09,600 --> 00:01:13,640 Speaker 1: but white squares with black letters. Now traffic sign codes 21 00:01:13,680 --> 00:01:17,399 Speaker 1: throughout the twentieth century have recommended several different variations on 22 00:01:17,520 --> 00:01:20,959 Speaker 1: the basic design. For example, in nineteen thirty five, the 23 00:01:21,080 --> 00:01:24,560 Speaker 1: United States got its first official manual on Uniform Traffic 24 00:01:24,600 --> 00:01:27,959 Speaker 1: Controlled Devices, which said stop signs should be a yellow 25 00:01:28,040 --> 00:01:31,560 Speaker 1: octagon with black or red lettering. It wasn't until the 26 00:01:31,640 --> 00:01:34,600 Speaker 1: nineteen fifty four revision of this nineteen forty eight edition 27 00:01:34,680 --> 00:01:37,120 Speaker 1: of the manual that the red octagon with white letters 28 00:01:37,200 --> 00:01:40,560 Speaker 1: became the law of the land. According to that document, 29 00:01:40,880 --> 00:01:43,200 Speaker 1: the red color is consistent with the accepted use of 30 00:01:43,200 --> 00:01:44,959 Speaker 1: a red light as a stop signal and of the 31 00:01:45,040 --> 00:01:48,560 Speaker 1: color red as a special warning of danger. Furthermore, they 32 00:01:48,600 --> 00:01:51,200 Speaker 1: explained that the original decision to use yellow instead of 33 00:01:51,240 --> 00:01:54,080 Speaker 1: red was because red pigments were more likely to fade 34 00:01:54,120 --> 00:01:57,080 Speaker 1: over time with exposure to the elements. However, by the 35 00:01:57,160 --> 00:01:59,760 Speaker 1: nineteen fifties, the state of California had solved the problem 36 00:01:59,840 --> 00:02:03,400 Speaker 1: by using porcelain enamel to protect their precious red signs, 37 00:02:03,640 --> 00:02:06,920 Speaker 1: and higher durability red paints were becoming more widely available, 38 00:02:07,480 --> 00:02:12,080 Speaker 1: and like that, red became the new yellow. But there's 39 00:02:12,120 --> 00:02:15,560 Speaker 1: a question that goes deeper than uniform traffic signaling protocol. 40 00:02:16,280 --> 00:02:19,120 Speaker 1: Why red is there any reason to think a red 41 00:02:19,120 --> 00:02:21,600 Speaker 1: stop sign would work better than any other color at 42 00:02:21,600 --> 00:02:24,639 Speaker 1: getting drivers to stop zooming straight through intersections at eighty 43 00:02:24,680 --> 00:02:28,480 Speaker 1: eight miles per hour. One fairly obvious answer is that 44 00:02:28,600 --> 00:02:30,440 Speaker 1: red is not as likely to blend in with the 45 00:02:30,520 --> 00:02:34,240 Speaker 1: landscape as some other colors. This explains why the highway 46 00:02:34,240 --> 00:02:37,360 Speaker 1: administration has repeatedly rejected our proposal for a green and 47 00:02:37,400 --> 00:02:41,919 Speaker 1: brown camouflage patterned stop sign. Another important point is that, 48 00:02:42,160 --> 00:02:45,080 Speaker 1: like the aforementioned manual says a red is a color 49 00:02:45,120 --> 00:02:48,919 Speaker 1: we consistently use to identify warnings and peril a think 50 00:02:48,960 --> 00:02:51,520 Speaker 1: about the wrong way sign and the do not enter sign. 51 00:02:52,200 --> 00:02:55,959 Speaker 1: Having consistent color coding helps drivers learn to identify specific 52 00:02:56,000 --> 00:02:59,240 Speaker 1: colors with specific messages. So even if you only catch 53 00:02:59,280 --> 00:03:00,919 Speaker 1: the hint of a red sign out of the corner 54 00:03:00,960 --> 00:03:03,440 Speaker 1: of your eye, you're more likely to react with caution 55 00:03:03,680 --> 00:03:06,520 Speaker 1: the way you've been taught. There are also some behavioral 56 00:03:06,560 --> 00:03:09,240 Speaker 1: research findings that might point to the inherent power of 57 00:03:09,280 --> 00:03:12,440 Speaker 1: the color red to command our obedience. For example, a 58 00:03:12,480 --> 00:03:15,720 Speaker 1: twenty eleven study published in Psychological Science found that male 59 00:03:15,760 --> 00:03:19,239 Speaker 1: recis monkeys under test conditions were less likely to steal 60 00:03:19,280 --> 00:03:22,720 Speaker 1: apple slices from human experimenters who were dressed in red. 61 00:03:23,320 --> 00:03:25,320 Speaker 1: The monkeys didn't seem to care about the gender of 62 00:03:25,320 --> 00:03:28,040 Speaker 1: the human experimenter and were not deterred by green or 63 00:03:28,080 --> 00:03:30,560 Speaker 1: blue clothing, but a red hat and T shirt were 64 00:03:30,680 --> 00:03:34,680 Speaker 1: enough to make the monkeys cautious about swiping that fruit. Now, 65 00:03:34,720 --> 00:03:37,520 Speaker 1: it's important not to read too much into that result. 66 00:03:37,640 --> 00:03:40,440 Speaker 1: The study was done on monkeys who could be reacting 67 00:03:40,480 --> 00:03:42,880 Speaker 1: to red for all kinds of reasons, but it at 68 00:03:42,960 --> 00:03:46,000 Speaker 1: least suggests the possibility that there is a primate instinct 69 00:03:46,040 --> 00:03:50,080 Speaker 1: to associate red with dominance or authority, and if humans 70 00:03:50,080 --> 00:03:53,400 Speaker 1: share this hypothetical primate instinct, the difference between a red 71 00:03:53,440 --> 00:03:55,520 Speaker 1: stop sign and a yellow stop sign might be the 72 00:03:55,520 --> 00:03:59,160 Speaker 1: difference between stop and the name of the law. And hey, hey, 73 00:03:59,400 --> 00:04:01,400 Speaker 1: hey guys, it might be nice if you've came to 74 00:04:01,440 --> 00:04:04,320 Speaker 1: a halt or you know, turned off your nitro boosters. 75 00:04:10,280 --> 00:04:12,800 Speaker 1: Today's episode is based on a video script written by 76 00:04:12,880 --> 00:04:15,880 Speaker 1: Joe McCormick for the brain Stuff YouTube channel, which is 77 00:04:15,920 --> 00:04:18,320 Speaker 1: a thing that we used to have to hear more 78 00:04:18,320 --> 00:04:20,720 Speaker 1: from Joe check out his podcast Stuff to Blow your Mind. 79 00:04:21,320 --> 00:04:24,360 Speaker 1: Brain Stuff is production of iHeartRadio in partnership with houstuffworks 80 00:04:24,360 --> 00:04:26,880 Speaker 1: dot com and it is produced by Tyler Klang. Four 81 00:04:26,920 --> 00:04:30,680 Speaker 1: more podcasts my Heart Radio, visit the iHeartRadio app, Apple Podcasts, 82 00:04:30,760 --> 00:04:32,600 Speaker 1: or wherever you listen to your favorite shows.