1 00:00:01,920 --> 00:00:07,200 Speaker 1: Welcome to brain Stuff. Production of iHeart Radio. Hey brain Stuff, 2 00:00:07,240 --> 00:00:10,039 Speaker 1: I'm Lauren Vogelbaum in today's episode is another classic from 3 00:00:10,080 --> 00:00:15,040 Speaker 1: our archives. This one concerns an actual bit of brain stuff. 4 00:00:15,680 --> 00:00:19,680 Speaker 1: Why scratching our heads may have developed as an unconscious 5 00:00:19,760 --> 00:00:25,920 Speaker 1: gesture of thought or confusion? Hey brain Stuff, Lauren Vogelbaum. Here. 6 00:00:26,360 --> 00:00:29,320 Speaker 1: If you've ever had the distinct pleasure of sourcing stock 7 00:00:29,360 --> 00:00:32,480 Speaker 1: photos for any reason, you've likely come across a whole 8 00:00:32,560 --> 00:00:36,560 Speaker 1: lot of laughing women eating salads alone. But you've also 9 00:00:36,600 --> 00:00:40,120 Speaker 1: probably stumbled upon a truckload of people scratching their heads 10 00:00:40,320 --> 00:00:44,320 Speaker 1: to symbolize confusion, deep thought, or perhaps a bad case 11 00:00:44,320 --> 00:00:48,320 Speaker 1: of dandruff scalp dryness. Aside, how exactly did the head 12 00:00:48,320 --> 00:00:52,760 Speaker 1: scratch come to symbolize intellectual processes? Some people believe that 13 00:00:52,840 --> 00:00:56,520 Speaker 1: certain automatic gestures are simply natural expressive motions that are 14 00:00:56,560 --> 00:01:00,640 Speaker 1: Caveman predecessors passed down to us. San Diego Read columnist 15 00:01:00,680 --> 00:01:04,399 Speaker 1: Matthew Alice wrote this about it. One popular explanation for 16 00:01:04,440 --> 00:01:07,319 Speaker 1: any hand to head movements is that their frustrated aggression 17 00:01:07,600 --> 00:01:11,240 Speaker 1: a reversion to the natural movements of our rock throwing ancestors. 18 00:01:11,640 --> 00:01:14,160 Speaker 1: If you watch a small child strike at something, he'll 19 00:01:14,240 --> 00:01:16,319 Speaker 1: raise an arm over his head and bring it forward 20 00:01:16,400 --> 00:01:20,360 Speaker 1: in an arc. It's a natural, unstudied movement, not much finesse, 21 00:01:20,600 --> 00:01:23,840 Speaker 1: but for a caveman, it got the job done. Alice 22 00:01:23,880 --> 00:01:27,920 Speaker 1: also pointed to a possible anthropological explanation for head scratching. 23 00:01:28,480 --> 00:01:31,560 Speaker 1: He wrote, when we're wrestling with some naughty problem, we 24 00:01:31,600 --> 00:01:35,440 Speaker 1: experience feelings of frustration, perhaps some anger, and before we 25 00:01:35,480 --> 00:01:37,800 Speaker 1: know it, our hand flies up in the air. But 26 00:01:37,880 --> 00:01:40,480 Speaker 1: hold it. In these modern times, it's not polite to 27 00:01:40,520 --> 00:01:43,319 Speaker 1: bash the guy who asked the question, so instead we 28 00:01:43,440 --> 00:01:46,479 Speaker 1: deflect attention from the movement and scratch or rub our 29 00:01:46,520 --> 00:01:49,680 Speaker 1: head or chin or neck. In a two thousand nine 30 00:01:49,760 --> 00:01:53,880 Speaker 1: article for Psychology Today, author and former FBI counter intelligence 31 00:01:53,880 --> 00:01:57,320 Speaker 1: agent Joe Navarro wrote, when we are under stress, our 32 00:01:57,360 --> 00:02:01,680 Speaker 1: brain requires a certain amount of hand to body touching, handwringing, 33 00:02:01,720 --> 00:02:06,760 Speaker 1: forehead rubbing, temple massaging, lip touching, etcetera. These pacifiers served 34 00:02:06,840 --> 00:02:11,880 Speaker 1: to soothe the individual when there is negative limbic arousal, fear, stress, etcetera. 35 00:02:12,919 --> 00:02:16,200 Speaker 1: Recent research seems to back up this stress theory and 36 00:02:16,400 --> 00:02:19,560 Speaker 1: add another unexpected layer to the story. In a two 37 00:02:19,560 --> 00:02:23,160 Speaker 1: thousand seventeen study, which was published in the journal Scientific Reports, 38 00:02:23,480 --> 00:02:26,959 Speaker 1: Scientists who observed forty five rees monkeys found that scratching 39 00:02:27,040 --> 00:02:29,720 Speaker 1: was more likely to occur in times of heightened stress, 40 00:02:29,880 --> 00:02:32,160 Speaker 1: like standing in the presence of a high ranking or 41 00:02:32,240 --> 00:02:36,640 Speaker 1: unfamiliar monkey. It turns out monkeys who scratched were significantly 42 00:02:36,760 --> 00:02:40,880 Speaker 1: less likely to be attacked by those threatening strangers. Lead 43 00:02:40,880 --> 00:02:44,320 Speaker 1: author Jamie Whitehouse said in the study, as scratching can 44 00:02:44,360 --> 00:02:47,080 Speaker 1: be a sign of social stress, potential attackers might be 45 00:02:47,080 --> 00:02:51,560 Speaker 1: avoiding attacking obviously stressed individuals because such individuals could behave 46 00:02:51,600 --> 00:02:55,160 Speaker 1: unpredictably or be weakened by their stress, meaning an attack 47 00:02:55,280 --> 00:03:00,200 Speaker 1: could be either risky or unnecessary. And meanwhile, itching is 48 00:03:00,240 --> 00:03:03,880 Speaker 1: still a pretty mysterious phenomenon to scientists, but recent research 49 00:03:03,919 --> 00:03:07,800 Speaker 1: suggests the tickly sensation isn't necessarily a mild form of pain, 50 00:03:08,120 --> 00:03:11,320 Speaker 1: but its own distinct occurrence caused by a molecule that 51 00:03:11,440 --> 00:03:14,080 Speaker 1: sends a message from the heart to the spinal cord. 52 00:03:15,200 --> 00:03:18,600 Speaker 1: So while there's no single explanation for this head scratcher, 53 00:03:18,960 --> 00:03:21,320 Speaker 1: you know what was coming, it appears that acting out 54 00:03:21,360 --> 00:03:24,480 Speaker 1: your anxiousness with this stereotypical tick could keep you in 55 00:03:24,520 --> 00:03:33,440 Speaker 1: the good graces of others. Today's episode is based on 56 00:03:33,440 --> 00:03:35,960 Speaker 1: the article why do we scratch our heads when We're thinking? 57 00:03:36,120 --> 00:03:39,120 Speaker 1: On how stuff works dot Com written by Michelle Konstantinovski. 58 00:03:39,440 --> 00:03:41,720 Speaker 1: Brain Stuff is production of by Heart Radio in partnership 59 00:03:41,720 --> 00:03:43,600 Speaker 1: with how stuff works dot Com, and that's produced by 60 00:03:43,640 --> 00:03:46,640 Speaker 1: Tyler Klang and Ramsey Out. For more podcasts from my 61 00:03:46,680 --> 00:03:49,760 Speaker 1: heart Radio, visit the I heart Radio app, Apple Podcasts, 62 00:03:49,840 --> 00:03:51,640 Speaker 1: or wherever you listen to your favorite shows.