Learn about how people synchronize their heart rates when listening to a story; and vampire bats meeting up for meals. You’re invited to join Cody Gough and Ashley Hamer for a special live stream celebration to commemorate the release of Curiosity Daily’s 1,000th episode next week! Register for free here: https://www.eventbrite.com/e/curiosity-dailys-1000th-episode-celebration-tickets-191163133077 People synchronize their heart rates when listening to a story, even when they're in different places by Grant Currin When Choirs Sing, Many Hearts Beat As One. (2013, July 10). NPR.org. https://www.npr.org/sections/health-shots/2013/07/09/200390454/when-choirs-sing-many-hearts-beat-as-one UCL. (2017, November 17). Audience members’ hearts beat together at the theatre. UCL Psychology and Language Sciences. https://www.ucl.ac.uk/pals/news/2017/nov/audience-members-hearts-beat-together-theatre Pérez, P., Madsen, J., Banellis, L., Türker, B., Raimondo, F., Perlbarg, V., Valente, M., Niérat, M.-C., Puybasset, L., Naccache, L., Similowski, T., Cruse, D., Parra, L. C., & Sitt, J. D. (2021). Conscious processing of narrative stimuli synchronizes heart rate between individuals. Cell Reports, 36(11), 109692. https://doi.org/10.1016/j.celrep.2021.109692 Tibi Puiu. (2021, September 14). Our heart rates synchronize when closely listening to the same stories. ZME Science; ZME Science. https://www.zmescience.com/medicine/mind-and-brain/our-heart-rates-synchronize-when-closely-listening-to-the-same-stories/ The Project Gutenberg E-text of Twenty Thousand Leagues Under the Sea (slightly abridged), by Jules Verne. (2016). Gutenberg.org. https://www.gutenberg.org/files/164/164-h/164-h.htm Vampire bats meet up with friends for lunch by Grant Currin Vampire bats may coordinate with “friends” over a bite to eat. (2021, September 23). EurekAlert! https://www.eurekalert.org/news-releases/928884 Ripperger, S. P., & Carter, G. G. (2021). Social foraging in vampire bats is predicted by long-term cooperative relationships. PLOS Biology, 19(9), e3001366. https://doi.org/10.1371/journal.pbio.3001366 Spivack, E. (2021, September 28). Vampire bats rendezvous with their friends when dining out. Popular Science. https://www.popsci.com/animals/vampire-bats-eat-together/ Vampire bat adoption episode: https://www.curiositydaily.com/vampire-bats-adopt-babies-too/ Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Learn about how people synchronize their heart rates when listening to a story; and vampire bats meeting up for meals.
You’re invited to join Cody Gough and Ashley Hamer for a special live stream celebration to commemorate the release of Curiosity Daily’s 1,000th episode next week! Register for free here: https://www.eventbrite.com/e/curiosity-dailys-1000th-episode-celebration-tickets-191163133077
People synchronize their heart rates when listening to a story, even when they're in different places by Grant Currin
Vampire bats meet up with friends for lunch by Grant Currin
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/synced-heartbeats-during-stories-vampire-bats-social-meals
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about how people synchronize their heart rates when listening to a story; and how vampire bats meet up with friends for lunch.
CODY: Let’s satisfy some curiosity.
People synchronize their heart rates when listening to a story, even when they're in different places by Grant Currin (Cody)
Here’s something surprising: when people sing in a choir or see a play together, their heartbeats tend to synchronize. Now, new research has found that the same thing can happen even when people aren’t in the same room. Even cooler, this may serve as a window into consciousness itself.
Here’s how the study began: [19th century patrician accent] “The year 1866 was signalised by a remarkable incident, a mysterious and puzzling phenomenon, which doubtless no one has yet forgotten.” That’s the first line of 20,000 Leagues Under the Sea, a science fiction novel by Jules Verne. Participants listened to the audiobook while researchers monitored their heart rates. Even though the listeners were isolated, their hearts tended to follow the same general pattern: they would beat faster at some points in the story and slower at others.
That’s a big deal, since past research on heart rate synchronization hasn’t been able to tell whether it’s the activity itself that causes the effect, or some physical or social interaction between members of the audience. This shows that there’s something about the story that makes everyone’s heart beat faster.
But the story didn’t even have to be a nailbiter. For the next phase of the study, participants watched educational videos from popular YouTube channels (shoutout to minutephysics and Kurzgesagt - In a Nutshell). These videos are great, but they aren’t anywhere near as emotionally engaging as a sci-fi novel. And the viewers’ heart rates? They still synched up.
Then the researchers threw a twist into the experiment: they had the participants count backwards while watching the videos. That distraction made the pattern fall apart completely. That told the researchers that listeners are subconsciously controlling their heart rates based on what they’re consciously paying attention to.
In one last phase of the experiment, the researchers compared healthy volunteers with people in comas. Both groups listened to the same children’s story, and the participants who were unwell had weaker heart rate synchronization than the healthy volunteers. But get this: the listeners in comas whose heart rates were more in sync with the story had a higher-than-average chance of regaining consciousness within six months. That could be the biggest takeaway here because measuring consciousness is really hard. For unresponsive patients, stories might be the window into their minds.
All this got us wondering: if 19th century novels, educational videos, and children’s stories get people’s hearts beating in the same rhythm, do podcast episodes do the same thing?
Vampire bats meet up with friends for lunch by Grant Currin (Ashley)
Vampire bats sound scary. I mean, yeah, as dusk falls, they take to the skies to seek out cattle and feast on their blood. Guilty as charged. But they’re more than parasites. A study on bats in Panama is shedding fresh light on their rich, nuanced social lives. Which they nurture over drinks...of blood.
Researchers have known for a long time that female vampire bats are really good at cooperating when they’re hanging out at home. For individuals with close social bonds, that can mean grooming each other. Or it can mean sharing regurgitated blood with a pal who came up short on her nightly hunt. In a past episode, we even told you about one who adopted her friend’s baby when she died.
Vampire bats are a textbook example of social cooperation, but practically everything researchers know about their behavior is based on how they act in the roost. That’s hardly the full picture! So, to flesh out our understanding of these friendly bloodsuckers, researchers strapped tiny backpacks to 50 individuals so they could track what they were doing during their nightly feasts.
Half of the backpack-wearing bats had previously been in captivity. During that time, researchers had watched to see which bats became besties. Once the bats had solidified their bonds and the researchers had painstakingly mapped out their social networks, the scientists had taken those bats into the field and introduced them to a group of wild bats living in a hollow tree. The other half of the backpack trackers went on the wild bats as a control group.
As night fell, the bats left their tree one by one. This surprised the researchers because, again, female vampire bats are known for being such reliable friends. But the bats didn’t stay solo for long. As they flew through the pasture, they would occasionally call out to one another. It’s hard for human researchers to know what they were saying, but at least one of the calls had never been documented by scientists.
The bats foraged separately for the most part, but data from the tiny backpacks revealed that bats known to have strong social bonds would often end up next to each other on the same cow. To the researchers, it looked an awful lot like old friends meeting up for dinner. The behavior makes sense, but it had never been seen before.
When it comes to female vampire bats, friends may not always fly together, but they often dine together.
RECAP
CODY: Before we recap what we learned today, we wanted to mention something kind of exciting. Next Wednesday, November 3, will be Curiosity Daily’s ONE THOUSANDTH EPISODE. Don’t worry — I know we’re probably a part of your daily routine, so we won’t do anything totally off the rails. It’ll be more or less a regular episode. But! On top of that! We want to do something special to celebrate! So Ashley and I will be hosting a special livestream Wednesday evening, and you can participate.
ASHLEY: Yeah, stay tuned to Curiosity Daily and we’ll release more details Friday. But you can RSVP for the livestream using the Eventbrite link that we’ll include in today’s show notes. You should be able to see the show notes for this episode on whatever podcast app you’re using right now — just tap on the name of our episode and hopefully it’s not hard to find. CODY: If it is hard to find, just check the episode on curiosity daily dot com. Anyway! Let’s recap what we learned today to wrap up.
1. ASHLEY: People’s heartbeats synchronize when they’re listening to the same story — even when they’re not in the same room. That suggests that when studies have found heartbeat synchronicity between people in a theater audience or members of a choir, it probably was due to the activity itself and not some physical interaction between the people. Even cooler, people in comas who were better at synchronizing their heart rates to a children’s story were more likely to regain consciousness in six months. That means stories might be a window into the minds of unresponsive patients!
2. CODY: Female vampire bats will meet up for dinner and drinks with friends! These bats are known for their tight social bonds, but those bonds had only really been studied in the roost. So scientists attached trackers to a bunch of individuals to see how they behaved when they left home for food. Even though individuals would leave solo, bat friends would often meet up to slurp blood from the same cow. Aww.
[ad lib optional]
ASHLEY: The writer for today’s stories was Grant Currin.
CODY: Our managing editor is Ashley Hamer.
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!