Sunday, June 12, 2011

Emoting and Evolution

Ever wondered...
  • How facial expressions evolved?
  • Why we smile when we're happy rather than grimace?
  • Why we laugh?  Make grunting noises at unexpected or out of place events?
  • Why do we expel water from our eyes when we're sad? 
Seriously.  It makes no sense. 

The way we emote is arbitrary.  Imagine an alien coming to Earth and interacting with a human for the first time.  A human representative approaches the creature and smiles warmly to signify a peaceful demeanor and intentions.  However, to the alien, bearing one's teeth (or equivalent masticating anatomy) is a severe threat (as it is with many animals and primates!!).  The opposite message intended is received.  Am I the only one that thinks it weird that smiling could result in the obliteration of the human race?  The only reason I bring that up is to remind you that the expression of emotion as we know it, and take for granted, is emphatically not universal, inevitable or necessary.  

But it is intensely personal.  

It is immensely powerful.

Think about this: would you rather have no face or be a quadriplegic?   

These displays are deeply biological and surprisingly cross cultural.  There have been studies that have shown pictures to remote tribes and asked what emotion the face exhibited and there was near unanimity in the answers.  Other studies with infants, dogs and primates have further demonstrated how widely recognized our emotional displays are.

One fundamental desire that evolution often has that I should point out is the desire to keep groups together.  Individuals are vulnerable to starvation, attack, parasites and predators.  Social animals have complex means of cementing relationships to avoid fracturization such as morality, emotional bonds, communication, grooming, synchronized behavior, etc.  The below is just one manifestation of how our ancestors used communication (and quite possibly one of the first forms) to operate as a collective unit.

You'll notice, as Darwin himself did, that many emotional opposites are expressed by opposite facial contortions--anger has eyebrows down and lips tight while happiness has eye brows up and lips wide open, et cetera.

Darwin also used the term 'serviceable habit'.  The idea is that the display was once just simply a motion in service of a behavior.  Examples help.  The anger display is bearing one's teeth and lowering the eye brows.  Teeth were exposed when our ancestors were about to bit and eyebrows might help focus, shield light, protect eyes, etc.  The disgust display was once in service of vomitation.

  • Joy/Happiness/Smiling
      • To put it plainly, our ancestors that could show they were happy had more kids than those that couldn't
        • Either or sexual selection reasons--people like happy people
        • Or, for natural selection reasons 
          • Cement bonds
          • Perpetuate prosocial behavior
          • It's been pointed out that chimpanzees use teeth bearing to express submission.  It's interesting to think how we've changed (and chimps use the ancestral form of facial expression), chimps have changed (and we're ancestral) or our common ancestor had something totally different to express happiness and/or submission.
          • To express a success--like the finding of food, social/battle victory

  • Sorrow/Sadness/Crying
      • Garner emotional support
      • Express defeat ("I give up.")
      • Express pain ("So stop hurting me.")
      • Express a need--such as an infant
        • This might  be a big avenue that caused the evolution of crying--a child's whine
  • Laughter
      • This is one that's very similar in chimpanzees
      • Releases tension
      • Establishes hierarchy--by making someone the brunt of a joke
      • Ever noticed how crying can sound like laughing?  Or that sometimes you tear while laughing?  I might imagine that the contexts are so different and readily apparent that there isn't much selective pressure to distinguish the two.  Funny coincidence, though.

  • Blushing
      • Darwin had a tough time with this.  Why would someone want others to know that they're embarrassed?
      • Perhaps as a visual apology

  • Fear
      • To warn others
      • To show defeat

  • Surprise (Separate from fear)
      • This one's tough for me to think about.  The most I've gotten so far is that maybe it's a display filler--like it buys a person time to process an event so that an inappropriate display isn't chosen.  For example, something shocking happens and it might be very socially inappropriate to show anger when happiness is expected so showing a surprised face first buys time to decide to then smile.  Maybe...

  • Anger 
      • Inspire fear, submission
      • Challenge others

  • Disgust
      • To express disapproval without a desire to fight
      • To warn others of the insalubrious  
Relatively easy to fake:
  • Smile
  • Laughter (at least the chuckle-at-your-boss's-dumb-joke king)
  • Anger 
  • Disgust

Relatively hard to fake (as in you have to be a highly skilled actor to do it):
  • Embarrassment
  • Fear
  • Real laughter
  • Crying
The ones that are easy to fake are ones that our ancestors needed to learn how to lie about. There may have been selective pressure to pretend to have an emotion that you don't really feel in order to advance social status or cohesion.

Emotional displays I wish evolution gave us (Please think about how awesome it'd be to see the below):
  • Honesty/sincerity (As in, I wish it were harder to fake.)
  • Empathy
  • Understanding
  • Gentleness
  • Patience
  • Female arousal
  • Love
  • Gratitude

Pictures are from here, here, here, here, here, here, and here.


  1. Yup. It looks like you have already come across Paul Ekman's interesting and groundbreaking work.

    "The below is just one manifestation of how our ancestors used communication (and quite possibly one of the first forms) to operate as a collective unit."

    Yup. Equally puzzling and interesting is facial identification. Our ability to identify faces may be innate. But moreover, we can instantaneously tell a face's gender and age, and we can identify many, many different people (a thousand or so?) by their faces, even if we haven't seen them for years or even decades.

  2. Thank you for citing a reference! My blogs are far too often bereft of any. I hope that gives something for people to look up if they want to dig deeper.

    Yes! And how we see them even when they aren't there!! Like this--> :) That's two dots and a curved line and somehow our facial recognition software construes it into a face. We're so good we see them when they aren't even there!


Please comment! You can comment anonymously! Please send ideas and topics to research and post on!!!