Where Do Our Facial Expressions Come From?

Where Do Our Facial Expressions Come From?

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What kind of day do you think this woman is
having? And what’s going on here? And probably it isn’t hard to imagine how
these two are feeling, right? That’s because most humans are really good
at silently communicating and interpreting a whole range of emotions using only facial
muscles. Whether it’s voluntary or involuntary, a
simple curled lip, raised eyebrow, or crinkled nose says a lot. In fact, many psychologists think that some
of our basic facial expressions, like the ones that express anger, fear, happiness,
surprise, sadness, and disgust are innate not learned, and are universal across
cultures. That’s because these basic expressions probably
started out as practical reactions to stimuli, and eventually became associated with emotions. In his appropriately-named book The Expression
of the Emotions in Man and Animals, published in 1872, Darwin helped popularize the idea
of universality: that we’re born to express emotions in a certain way. He suggested that we humans inherited our
emotional expressions from our ancestors, and that these expressions helped increase
survival by facilitating communication in social groups. He also proposed that our expressions adapted
to environmental stimuli, something that I will come back to in a minute. Darwin’s book even came with olden-day photos
of people demonstrating facial expressions, like these pictures of people trying their
best to show what grief looks like. In the late 1960s, psychologist Paul Ekman
began testing Darwin’s universality idea by traveling around and conducting lots of
independent, cross-cultural studies. In New Guinea, for example, he encountered an isolated culture that had never seen outsiders before. He told subjects brief emotional stories like
“old friends are coming to visit,” or “you just stepped on a rotten dead pig,” and he showed them a set of three different photographs of facial expressions. Ekman found that they usually picked the expression
that he expected them to associate with the emotion in the story, like a frown for sadness. So even though this culture was very isolated
from ours, the population used the same basic facial expressions. Other studies have found that infants, as
well as people who were born blind, also use the same facial expressions, without being taught which expressions go with which emotions. By the 1970s, Ekman and other researchers
had started working on a more objective way to measure these universal facial expressions, by documenting muscle activity on the face itself. They compiled what’s known as the Facial
Action Coding System, or FACS. The system looks at muscle engagement, noting the intensity, duration, and asymmetry of an expression. By comparing the muscle movements on someone’s
face with what an expression is supposed to look like, psychologists can use the FACS
to help distinguish emotions. Like, telling real smiles from fake ones, to detect if someone is lying,
or to identify certain emotions in people who can’t express themselves verbally. So it seems like we’ve probably evolved
with some basic facial expressions built-in. And a 2013 study out of Cornell University
looked at why. The researchers had their subjects make neutral,
scared, and disgusted expressions, and then measured how much light made it to their retinas
with each expression. And it turns out that facial expressions may
have first evolved to help us better react to our environments by controlling our sensory input, like the amount of light we let into our eyes. Say you’re walking through the jungle, for
example, and suddenly you hear a loud crash. It scares you, and as an expression of fear
sweeps across your face, you widen your eyes. This immediately expands your field of vision,
letting in more light, and heightening your visual sensitivity to help you locate any
danger. But if, say, you accidentally step on a mound
of mystery poo in the park, you’ll do something very different. As you recoil in disgust, your eyes narrow,
letting less light in as you sharpen your focus to examine your soiled foot. That classic disgusted nose-wrinkling also
helps decrease the size of your nasal cavity and let less air flow through it, presumably
so you don’t have to smell as much of whatever is giving you the nasties. This suggests that how you feel actually
shapes your perception of reality, and how much light hits the back of your eye. Some social communication may have evolved
from these reactions to outside stimuli, which also supports Darwin’s idea that basic facial
expressions are universal. Though there is definitely a learned component
to our facial expressions, too. If you’ve ever nodded politely during a
relative’s political rant, when really you felt like screaming inside, you know that
we learn to control our faces and mask emotions in certain social situations. So, many facial expressions are probably innate.
But managing them is a whole different story. Thank you for watching this episode of SciShow,
which was brought to you by our patrons on Patreon, thank you to all of you, so much
for helping support this show. If you want to become one of those people, if you aren’t already, you can go to patreon.com/scishow. And don’t forget to go to youtube.com/scishow and subscribe!


  1. Hi Hank. Why are some people right-handed, yet use their left leg as the dominant one? I'm a gymnast and at my gym I've noticed that the percentage of girls that are left-leg dominant (meaning they turn on their left leg, hurdle with their left leg in front, leap with their left leg, etc.) is way more than just 10%. In fact, it's closer to 50%. And in some cases they could be right-handed, yet they feel most comfortable using their left leg for gymnastics. How does this happen?

  2. happiness is a positive emotion so I should widen my eyes so I can see the stimulus that made me happy better right? but I'm Asian and when I smile my eyes get smaller. explain.

  3. I had a group report yesterday about expressions and it was good, but it would have been better if they uploaded this earlier. 🙂

  4. I have a question, wondering if anybody could answer this. Sorry in advanced if this is stupid.

    If you're not supposed to add water to acid in fear of a violent reaction, why doesn't this happen when with your stomach acid when you drink water, or when any animal drinks water?

  5. when i look at the sun i dim my eyes down or cover them with my hand, so was i born with that facial expression?

  6. I just became aware of the fact that Hank's ears are very perky and out there. I feel like that time I notices DBZ character's ears for the first time.

  7. I love the comment about silently nodding at your relative's political ideas and screaming on the inside. I've heard some pretty racist and crazy things!

  8. I love the information, but listening to Hank talk is like nails screeching down an infinite chalkboard.

    Take some pauses and close your jaw so I digest information in segments. Silence is a virtue.

  9. Do you think gasping in surprise or fear is the same way? Like super fast way to get a bunch of oxygen into our system in preparation for fight/flight?

  10. Only showing women in the begging is so sexist. Sorry I just left the comments section from the Y chromosome video, was a little on edge lol

  11. so… non primates emotions are "readable" in the same way (thinking about surprised cat… sad dogs… not amused… hamster? whatever)? Or is the animals mimicking our facial expressions so they can comunicate with us? Or is it just us thinking we can "read" those emotions and we are plain wrong about? In a nutshell: do non primates animals have the same facial expressions for the same emotions as humans do?

  12. urgent QQ: is it actually better to run in zigzag than straight when hunted by a bowman?
    is it worth the longer distance and other risks you take?
    please, scishow, i feel like you could set things better than "straight"!

  13. You guys helped me out on my science test today because I watch your vids and other science vids on YouTube…

  14. dey come from meme aliens because hunans brains are to complex for creatures on earth this is just a scientific fact but who are the meme aliens? some say jesus christ lord of light, savior of the broken, beaten, and damned lord juese meme alien please watch over the meme babies

  15. This video could use a lot more on the issues of what isn't universal. There's a good bit of research out there that will tell you, for example, about how something as simple as a smile can have a lot of culture around it. Smile=happy might be universal, but a smile can communicate a lot more: polite friendliness, embarrassment, sexual interest, etc, and these things are much more cultural. Furthermore, culture dictates a lot about when it is normal or appropriate to smile, etc.

    For example, in America, smiling is very important. Employees should smile to costumers. You should smile when you go to a job interview, or meet new people for business. Americans value friendliness, and we show it with smiles.

    In Russia though, smiling too much is weird. You shouldn't smile to strangers or new people, not until you start getting to know them and then have a reason to smile. Russians value that honesty in expression. Americans often think Russians are cold and scary, because they don't smile so much, but Russian's often think Americans are weird and dumb, because they go around smiling all the time.

    Here are just some things on the topic, whatever I could find when I did a presentation on it in college, I'm sure there's more.

    Ekman, P. (1972). Universals and cultural differences in facial expressions of emotion. In J. Cole (Ed.), Nebraska Symposium of Motivation, 1971 (Vol. 19, pp. 207–283). Lincoln: University of Nebraska, Press.
    Kotchemidova, C. (2005). From good cheer to" drive-by smiling": a social history of cheerfulness. Journal of Social History, 39(1), 5-37.
    Krys, K., Hansen, K., Xing, C., Szarota, P., & Yang, M. M. (2014). Do Only Fools Smile at Strangers? Cultural Differences in Social Perception of Intelligence of Smiling Individuals. Journal of Cross-Cultural Psychology, 45(2), 314-321.
    Matsumoto, D. (1990). Cultural similarities and differences in display rules. Motivation and Emotion, 14, 195–214.
    Matsumoto, D., & Ekman, P. (1989). American-Japanese cultural differences in judgments of facial expressions of emotion. Motivation and Emotion, 13, 143–157.
    Matsumoto, D., & Kudoh, T. (1993). American-Japanese cultural differences in attributions of personality based on smiles. Journal of Nonverbal Behavior, 17(4), 231-243.
    Richmond, Y. (1996). From nyet to da: understanding the Russians (1st Ed.) Yarmouth, ME: Intercultural Press.
    Szarota, P. (2010). The mystery of the European smile: a comparison based on individual photographs provided by internet users. Journal of nonverbal behavior, 34(4), 249-256.
    Szarota, P. (2011). Smiling and happiness in cultural perspective. Austral – Asian journal of cancer, 10(4), 277-282.
    Wierzbicka, A. (1994). Emotion, language, and ‘cultural scripts’, in Kitayama, S. & Markus, H. (Ed.) Emotion and Culture: Empirical Studies of Mutual Influence. (pp. 130-196) American Psychological Association,Washington,
    Wierzbicka, A. (1995). Kisses, handshakes, bows: the semantics of nonverbal communication. Semiotica, 103 (2), 207-252
    Wierzbicka, A. (1999). Emotions Across Languages and Cultures: Diversity and Universals. Cambridge University Press,
    Wierzbicka, A. (2004). ‘Happiness’ in cross-linguistic & cross-cultural perspective. Daedalus, 133(2), 34-43.

  16. What I don't understand about the Ekman Study is why he chose to have them select a facial expression from a set of three, rather than to just see them make a facial expression. Was he trying to remove interpretation from his data (impossible, but often attempted)? Was he trying to maintain a metric that is quantifiable?
    If magically someone watching this video has studied this and knows I'd be interested to hear the rationale – it seems to me that by conducting the study as he did he brought in all of his cultural assumptions as context, rather than letting the interpretation of facial expressions emerge from the culture he was studying.

  17. It's worth noting that the conclusion of the Ekman study calls the facial expressions 'pan cultural' and not 'universal'. These are distinct ideas – the former requires situation within a culture, but does not discriminate which culture it's in. The latter is completely maturational and will happen to every normal person.

    Of course, that is my interpretation of those words – perhaps Ekman meant the two as synonyms.

  18. My laboratory developed a relatively cheap way to measure facial muscle activation – and even control a keyboard with muscle activation – so you can mimic Ekman's work at home – http://www.instructables.com/id/Typing-With-EMG-Using-MyoWare/

  19. Could you talk a bit about collective subconscious as well, such as the feeling of falling and jerking awake when we are falling asleep (because of our ancestors sleeping in trees)?

  20. If this interested you, go watch Lie To Me on Netflix 🙂  But keep in mind, the science are not fully agreeing about how universal these facial-expression actually are. Enjoy! ^^

  21. 0:38 Practical reactions to whom? O_o

    Also, I find it weird that in humans, a toothy smile or laugh denotes pleasure or happiness, while in our closest animal relatives and the rest of mammals, that baring of teeth is an aggressive display. Such an odd disparity. What changed it?

  22. Facial expressions may be innate, but gestures are learned. In Bulgaria, people nod their heads up and down to indicate "no" and side to side to signal "yes"– the exact opposite of what Anglophone Amercans do. My Bulgarian friend says he was constantly confused for the first couple of years he lived in the U.S.

  23. I swear I have no control over my facial expressions. People often ask my what's wrong because my neutral expression looks grouchy, and they ask why I'm smiling when I'm clearly upset. I don't even know how I manage to interact with anyone without getting snide comments every time.

  24. why do we have interests? is it environmental? part of genetics? ect.I've had this question for a long time, being a nerd in school I stand out a little and I would love to know why I became like this. BTW ur vids. r amazing.

  25. Just a question i thought would be cool to have answered: How fast would someone have to be running to run across water?

  26. I am a master of controlled emotion. Like when the dirt bad lies to my face and gets all defensive I have to smile at him and not beat him with something heavy for lying to my face.

  27. Sooo, are there facial expressions that have no basis in physically appropriate reactions to stimuli? You tease twice that all expressions have such a basis and then you name two examples and talk about some social communication having evolved from such reactions.

    Also, you could have used better examples for how facial expressions are shaped by social learning instead of using the fact that we can control emotion displays to some extent which is a whole different bag of worms.

  28. Wow, circular reasoning at it's best. Academia has been on a slippery slope since Darwin. Funny thing is they don't realize it's been downhill since then. Nietzsche declares God is dead and man enters the 20th Century and kills millions in the name of man.
    Thanks Chuck.

  29. Dear SciShow,

    This is an odd question. My friends and I have some pretty long hair. To our waists or longer. We keep our hair up almost all the time since it can get in the way of pretty much anything we do. However, each evening, we've all noticed that we collect quite a bit of hair in our butt cracks. Sometimes a lot of hair collects. We all wear clothing, bathe regularly, and keep our hair tied/braided/knotted up somehow.

    So why do we constantly find hair collecting in our cracks?

    I know this is a strange question to come from a grown woman and her friends, but we were curious and I figured, "Heck, ask Hank and the SciShow guys. They might know!" So here I am……asking.

    Thanks for your consideration.

  30. If aliens ever came to earth theyd probably be like "ugh what is with your face!? why are the muscles and skin always moving its disgusting!"

  31. I've known a few people that are really bad at reading expressions………Confusing things like anger for fear.
    Also everyone seems to think they can tell one someone is lying but their face reading is no better than a coin toss.

  32. When I try to watch this on my Apple TV; I get a SNHU commercial that crashes and I cannot see your material.

  33. So what was the component that was learned? It made it seemed like some emotions are learned and not innate, while the example was simply about controlling existing emotion.

  34. I don't think I ever raise my eyebrows, voluntarily doing this feel unnatural. Voluntarily lowering them brings feeling of working on something like a puzzle and that feels natural.

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