8 Truths and Myths About the Full Moon
With so many claims about the moon’s influence over everything from menstrual cycles to rainfall, SciShow is here to set the record straight with these 8 truths and myths about our moon.
Hosted by: Hank Green
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  • Demcheck

    Objectively, my cat goes CRAZY when it's full moon.

  • Jeff Mullins
    Jeff Mullins

    Not a myth. I've worked in call centers for 14 years and people get crazy during a full moon. I know people in the medical care field and they say their patients are whacky too.

  • OXOTNHK aka D3ath Patr0l
    OXOTNHK aka D3ath Patr0l

    Ovaries....ON THE MOOOOOON

  • iafozzac

    What about hair growing faster or slower depending on the moon phase of the time it was last cut? That one is a pretty popular myth here in Italy

  • InformalNarwhals

    hank: do full moons trigger seizures? me: * slight panic * video: myth me: * relieved * hank: but they do happen more often on the last quarter and darker nights and are somehow linked to lunar cycles me: * back to slight panic *

  • Alicia Gardner
    Alicia Gardner

    Sorry but I've been in healthcare for 20 years and I can attest that during full moons we see more incidents on those nights...just saying

  • Boi Mesa
    Boi Mesa

    Better not tell this to my girlfriend 😅

  • Norman Smith
    Norman Smith

    Grunion runs are affected by the moon. The grunion swawn only at the highest tides which are conteolk by the the moon. During the highest tide they run or in other words spawn. The eggs remain in the sand until the next high tide when they hatch.

  • rautermann

    Sorry to be pedantic, but these are MOON FACTS not FULL MOON FACTS. Bad title.

  • Forced2makethis Bloodyaccount
    Forced2makethis Bloodyaccount

    I doubt the menstruation study took into account the widespread and common use of contraception. It would be harder to get a large number of women not using contraceptives. That would be the study I would read.

  • Limerence

    Circuluniary rhythms could explain why women's periods on average are on a 29 day cycle when the moon is also on a 29 day cycle. Obviously not every women get's their period on the full moon and not every woman has a 29 day menstrual cycle, it's just the average. But if you remove a woman's sense of time (take away all natural time tellers, clocks, sunlight, etc) her period will be thrown off so your natural body clock could use the phases of the moon to know when to do menstrual stuff. I don't know about the chimpanzees, maybe they just don't notice the moon or count in days instead.

  • H Smith
    H Smith

    Never dug in to police statistics then did you...

  • Regina Irene
    Regina Irene

    Ok, so you start out by saying a full moon doesn't affect people's behavior, and then immediately state it affects both the quality and quantity of sleep....which would directly affect human behavior. Am I missing something?

  • avinash bhujan
    avinash bhujan

    "Research actually has not found any connection". So does that mean it is definitely a myth? If you cannot prove something, does that automatically disprove it? You are implying that lack of evidence is evidence of nihility. Or does it mean that the research method is weak?

  • nebulaunfolding

    More babies are born under the full moon. Ask any experienced nurse in labor and delivery.

  • photondance

    Okay. I’m comfortable with coincidences. Coincidi?

  • liam redmill
    liam redmill

    Superb new discoveries natural👍

  • Theodore Seeber
    Theodore Seeber

    Hmm- a solution to speed up corral evolution: Blue spotlights shining on the ocean all the time, triggering more sex parties, thus triggering hyperevolution for warming oceans.

  • Aislin King
    Aislin King

    Hank, I think those shirts clash a bit

  • FriendlyShark Ce
    FriendlyShark Ce

    I apreciate that they didn't gender the users of the menstrual cicle app. Thank you for not using gendered language for that!

  • Watermelon Warriors
    Watermelon Warriors

    Dung beetle: oh, dis is not so hard. Me: dats a weird looking poop ya got der

  • MrWombatty

    Why no mention of werewolves?

  • Watermelon Warriors
    Watermelon Warriors

    It would be cool and scary to be a werewolf

  • Jessikah I’m 2 F’ N REAL
    Jessikah I’m 2 F’ N REAL

    In the south when we see a couple pregnant women we say (must be a full moon) 🌕!!!!

  • Jessikah I’m 2 F’ N REAL
    Jessikah I’m 2 F’ N REAL

    Omg😱😱😱 you the guy I watched for 4 years to get my degree from college online!!!!! It was you!!!! Thanks luv your Biology 🧬 videos SAVED ME!!!!!! I PASSED MANY TESTS!!!!! ❤️❤️❤️ I’ll never forget your voice!!!!

  • Ken O
    Ken O

    Isn't the most obvious one, the origin of the words lunacy and lunatic?

  • RyanWake bradtelle
    RyanWake bradtelle

    if the menstral cycle is a couionsidance then why did it change

  • Sandman

    there is always a different outcome between science tests and practical real world. You are more likely to get people acting crazy on a full moon. Control ab tests will always alter the outcome

  • - { Nay } -
    - { Nay } -


  • Amanda Powell
    Amanda Powell

    If women did not have all the chemicals running through it, you would find a greater correlation with the moon cycle. Not that everyone will start and stop their cycle on the same day; but you can correlate a daughter's cycle from their mother's cycle.

  • AgeingBoyPsychic

    10:30 Your moon seems to have a big chunk missing... Or is the grid pattern in front of the moon?

  • Funny Memes
    Funny Memes

    Annual Sex Festival is actually an underwater snowstorm...

  • Michal Grňo
    Michal Grňo

    0:15 Hank: Must be a full moon and- Also Hank: BUT!

  • Positron Decay
    Positron Decay

    3:23 That is so COOL!!

  • Lovely Doll Time
    Lovely Doll Time

    This video somehow reminds me of the Friday the 13th harvest moon in 2019.

  • kez kezooie
    kez kezooie

    This got me wondering about why scorpions would glow under UV light if it was something that put them in greater danger of predation. You'd think that natural selection would weed out this trait. Is there a metabolic reason for this trait? Is there something that is either beneficial or so necessary that it's let this trait survive?

    • SlyPearTree

      Their predators do not see in UV, at least I don't think so.

  • dreadthedays says
    dreadthedays says

    If you watch the moon cycle you will bleed on the full moon. This is pretty well know in celtic communities to reduce period pain and shorten the days as drastic as 4 dsys less. You do not need to do anything other than be aware of the moons current phase. Nearly everyone I have ever challengeed to try this alignment do agree in the effects.

  • Kay Carle
    Kay Carle

    What about the belief that full-term pregnant women are more likely to go into labour on the full moon? I've heard some midwives say that's not true, but that there is a spike in women being admitted to labour units when there is a thunder storm. Thoughts?

  • CrunchyLikeness

    I wasn't ready for Hank's shirt

  • Cat Poke
    Cat Poke

    The thumbnail is like a cryptic way of saying "The blood moon is rising..."

  • MultiRobotnik

    Water Bending.

    • bilias hour
      bilias hour

      its interesting when people say , its super small effect im sure it doesnt effect us ... but ... how do you know for sure?

  • Brian Steele
    Brian Steele

    Internal worms and parasites in the human body could be affected by the moons place in orbit. Causing them to release hormones in the body that could cause a disruption in the human hormones. This would cause erratic behavior if there was a over abundance of worms and parasites.

    • bilias hour
      bilias hour

      All of my EMT and police friends believe in the full moon bringing out the crazies. 😂

  • Chris Mcmullen
    Chris Mcmullen

    Wilder,weirder and harder to believe? A third of the oceans dying off? Animals loosing contact with the voice of God in these times. Where did the 'fallen one's fall from? Not that far away. Theres a reason people would be very uncomfortable with a very simple and understandable truth. The basis for what constitutes almost all of human knowledge is arrogance

    • aola wili
      aola wili

      night....especially in King's Cross Sydney...

  • Cats Are YES
    Cats Are YES

    Why is there a f*cking ovary on the moon in that thumbnail!

  • Caterfree10

    Clue is the best menstruation app bc it doesn’t force flowers on my nonbinary ass like every other period app on the App Store.

    • aola wili
      aola wili

      I must have miss- heard him when talking about creatures in Australia...I thought he said immoral trollops ...I've seen plenty of those doing the spawning thing on a dark moo

  • Frederic Louf
    Frederic Louf

    A vagina for thumbnail, somehow ? Should I understand that of all those eight stories, the menses' was the top relevant one or that the rough of a vajay's so much seemlier than that of a nudibranch ?

  • Jason Lueker
    Jason Lueker

    6:46? You said all scorpions, isn’t only venomous only?

  • bilias hour
    bilias hour

    Truth: Sailor Scouts fight evil by moonlight.

  • Private Person
    Private Person

    Where did you get the crime statistics ? When I charted the FBI reports of nation wide crime it was higher during the full moon. Less light polution back then.

  • Dreamweaver

    I disagree. I work in an ER. Things are crazier on full moon nights, and that is consistent every month. We get more assaults and more psych patients than on other nights with the only acception being around the holidays those things are higher. But yeah, the full moon does affect human behavior.

    • J P
      J P

      I agree. My parents had several Taverns (one at a time at different locations) and I noticed that 4 days before a full moon there was an increased likeliness of a bunch of crazy bar stool jerks to get into a violent fight, especially when it was a Friday and pay day at the same time. Was it a coincidence? No I don't think so because it happened over many years always shortly before or on a full moon.

    • bilias hour
      bilias hour

      Hey, Tom Cullen, how do you spell "awesome"? M-O-O-N spells "awesome," laws yes!

  • Raffa Luisi
    Raffa Luisi

    Kos or some say Kosm

  • James Bond
    James Bond

    Perhaps more seizures occur under less moonlight because there would be more contrast between the darkness and headlights, flashlights etc...?

  • xoobo vola
    xoobo vola

    "chimps have a menstrual cycle of a whopping 39 days" me: mmm so I'm a chimp. That's nice.

  • Nostr' Alma Mater
    Nostr' Alma Mater

    Yeah ummm...tell a 911 dispatcher that people don't get weirdest during a full moon....cause they do.

  • Ash Carruth
    Ash Carruth

    I want to call Shenanigans on the menstrual cycle test. I'm not saying that they are definitely linked, but how many of all of those people were on birth control, other medications that affect hormone levels, live in a city with constant high light pollution, Etc? There are just too many new variables in our modern life that wouldn't have been present when that myth got started

    • xoobo vola
      xoobo vola


  • Amber Smith
    Amber Smith

    All of my EMT and police friends believe in the full moon bringing out the crazies. 😂

  • Ilena Starbreeze
    Ilena Starbreeze

    its interesting when people say , its super small effect im sure it doesnt effect us ... but ... how do you know for sure?

  • okow tina
    okow tina

    Me: Oh, finally a video debunking all myths like the moon's influence on surgeries. Hank: Lemme tell you about dung beetles!

  • Starseed-bb

    i think human's sleep and menstrual cycles are linked to the moon for a reason. Full moon are religiously significant events in most of the world (a little bit less in Christianity and Islam, but these are organized religions that reject nature worship), so we can probably be pretty sure that humans have been getting up to some kind of special activity once a month or at every full moon. Women might have been consuming natural medicines to control their fertility cycle, and have used the moon to keep track of that which could slowly adjust their cycle to match up tot he moon's. Wouldn't be weird if tens of thousands of years of this have caused humans to have an internal clock sense of the lunar cycle.

  • psycronizer

    I must have miss- heard him when talking about creatures in Australia...I thought he said immoral trollops ...I've seen plenty of those doing the spawning thing on a dark moonlit night....especially in King's Cross Sydney...

    • okow tina
      okow tina

      early hominid multi-day hunting parties to correspond with the full moon. Thus, males home for the new moon and some consistency in the periodicity of menstruation with th