What are emotion expressions for?

December 23, 2011

(Medical Xpress) -- That cartoon scary face – wide eyes, ready to run – may have helped our primate ancestors survive in a dangerous wild, according to the authors of an article published in Current Directions in Psychological Science, a journal of the Association for Psychological Science. The authors present a way that fear and other facial expressions might have evolved and then come to signal a person’s feelings to the people around him.

The basic idea, according to Azim F. Shariff of the University of Oregon, is that the specific facial expressions associated with each particular emotion evolved for some reason. Shariff cowrote the paper with Jessica L. Tracy of the University of British Columbia. So fear helps respond to threat, and the squinched-up nose and mouth of disgust make it harder for you to inhale anything poisonous drifting on the breeze. The outthrust chest of pride increases both testosterone production and lung capacity so you’re ready to take on anyone. Then, as social living became more important to the evolutionary success of certain species—most notably humans—the expressions evolved to serve a social role as well; so a happy face, for example, communicates a lack of threat and an ashamed face communicates your desire to appease.

The research is based in part on work from the last several decades showing that some emotional expressions are universal—even in remote areas with no exposure to Western media, people know what a scared face and a sad face look like, Shariff says. This type of evidence makes it unlikely that expressions were social constructs, invented in Western Europe, which then spread to the rest of the world.

And it’s not just across cultures, but across species. “We seem to share a number of similar expressions, including pride, with chimpanzees and other apes,” Shariff says. This suggests that the expressions appeared first in a common ancestor.

The theory that facial expressions evolved as a physiological part of the response to a particular situation has been somewhat controversial in psychology; another article in the same issue of Current Directions in argues that the evidence on how emotions evolved is not conclusive.

Shariff and Tracy agree that more research is needed to support some of their claims, but that, “A lot of what we’re proposing here would not be all that controversial to other biologists,” Shariff says. “The specific concepts of ‘exaptation’ and ‘ritualization’ that we discuss are quite common when discussing the evolution of non-human animals.” For example, some male birds bring a tiny morsel of food to a female bird as part of an elaborate courtship display. In that case, something that might once have been biologically relevant—sharing food with another bird—has evolved over time into a signal of his excellence as a potential mate. In the same way, Shariff says, that started as part of the body’s response to a situation may have evolved into a social signal.

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2 / 5 (1) Dec 23, 2011
One of my main interests. Cross-phyletic communications through visual contact. It's how most non-humans gauge each others' intent when meeting in the wild for the first time. Body language and facial expressions are always specific to the animal, human or otherwise, but the internal dasein of an animal is always conveyed in the eyes clearly.

my experience is that no matter which animal I happen to be observing/studying, there is always a ritual of eye contact, gaze aversion and gaze tracking that has to come first in order for me to really be able to get close up to them, this holds true from humans on down to rodents.

I'm surprised gaze tracking and the like is not studied more often, it provides keen insights to cross-species social dynamics.
not rated yet Dec 23, 2011
Emotional reactions are genetically driven, instinctive, and common across species boundaries. Experience with one's own emotional reactions teaches each of us the association of each emotion and its physical expression. We learn to recognize the physical expressions when they appear in others through mimicry. [When you see someone else smile, you smile back, which reminds you of how you feel when you smile, and helps you understand what the other person must be feeling.]
This is simply non-verbal communication, which works as an adjunct to verbal communication to enhance our individual survival.
not rated yet Dec 23, 2011
It seems to me fundamentally misguided to consider the full range of possible emotional responses to have been individually selected for, reminiscent of the similar blind alley of ever more specialised modular nuclei some evolutionary biologists promote. I think such expressions are more emergent and their communicative value more incidental - capitalised upon perhaps, but through learning rather than hardwiring...

Just for example, i've no idea why we cry tears when sad - but clearly tear ducts evolved for reasons other than self expression. Does the excretion of ocular fluids really add anything fundamental - other than mess - to a crying face? It seems to me an emergent and incidental confluence of matters extraneous to emotion or communication. Likewise nasal mucous production when crying - is that selected for too? Where'd you draw the line..?

Surely emotions have developed as preparatory modes, priming our responses to the task at hand...
not rated yet Dec 23, 2011
oops - "evolutionary psychologists" not "biologists" of course...
not rated yet Dec 24, 2011
The greatest risk in a modelling of physical expression of emotions is a reductionistic approach - 1) there are no doubt anciently precursive genetic factors - both environmentally (exogenously) and proprioceptively (endogenously) triggered, 2) There is an FAP element (ethological, fixed action patterns) with biosemiotic releasers, 3) There is a memetic, socioculturally programmed behavioural element. These are/become neurologically embedded - some genomically in common over the whole human taxon, others differentiated geosocially, sociohistorically, and socioculturally in specific cultural clusters. The fact that amygdalic-thalamic reactivity is more primitively primary to amygdalic-thalamic-cortical (thought-out, cognitively nuanced) responses hints that emotional dynamics are at the very base of self-reorganisational reactivity to stimulus.

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