Emotional ExpressionCarol

Adrian

Introduction Cooperation among non-kin evolved as a

result of cooperators giving honest signals.

One such signal is involuntary facial expressions displaying positive emotions such as the “Duchenne” smiles.

Altruistic individuals display higher levels of positive emotion than non-cooperators.

Duchenne smiles correlate with altruistic tendencies only in situations requiring cooperation.

Duchenne smiles involve facial muscles surrounding the eyes and correlates with positive emotions.

Emotional expressivity can serve as a marker for an individual’s cooperative disposition.

Emotional expressivity makes it easier for cooperative individuals identified and chosen as interaction partners. Cooperators

More details Duchenne smiles are sometimes unrelated to altruistic tendencies.

Duchenne smiles have been observed when individuals defeat an opponent.

The situation in which emotions are displayed may determine the degree to which they reflect cooperative disposition.

Duchenne smile

Hypothesis “We predict that cooperators, defined as

those who make fair (i.e., 50-50) resource distributions as the proposer in the ultimatum game, would display higher levels of both positive and negative emotion than non-cooperators when they face unfair offers as the responder.”

Cheaters and Honest signalers

Displaying the correct emotion, both positive and negative would require mental effort, more than displaying positive emotion overall.

Individuals who honestly reveal their intentions to potential partners using involuntary signals of emotion such as facial expressions, blushing, or perspiration must commit to behaving in a cooperative manner,

Methods Twenty male participants recruited from

a research university in Japan with the promise of money.

Participant’s cooperation was measured as they played the ultimatum game.

The ultimatum game allows measurement not only displays of the negative expressions of emotions of both the proposer and the responder, but also their behavioral tendency to cooperate.

Social Value Orientation Pro-social are those who care about

their partner’s welfare. Pro-selfs are those who do not care

about partner’s welfare. This measure is used to qualify

behavior of cooperativeness (fair offers as the proposer ) › Identify true cooperators as opposed to a

prudent egoist who anticipates punishment for an unfair offer.

Procedure Participants escorted individually into

sound proof rooms – did not meet, see, or interact with each other.

Played truncated ultimatum game via computer with computer generated responses for the first 2 games.

1st game – intentional unfair proposal game

2nd game – non-intentional unfair proposal game

3rd game – used to identify cooperators

Emotional Expressions Each game had three phases pre-game,

response phase, and post game phase. Response phase was the focus of the

study. Video-taped the game players. Coders scored emotional signals of the

face associated with eight emotional categories; › anger, disgust, fear, sadness, contempt

(negative)› Duchenne smile (positive)› non-Duchenne smile, and surprise (neutral)

Results

Marginal finding for whether or not they were cooperative or non-cooperative F1,18=3.48, p=.08, ηp 2 =.16,

Emotional valence was also found to be significant F2,36=8.56, p=.001, ηp 2 =.32

Interaction between proposer type and game phase F2,36=5.62, p=.01, ηp 2 =.23

These findings support the idea that cooperators show more overall emotion (positive, neutral, and negative) than do non-cooperators…in regards to a negative situation› there was an overall lack of proposer type and

emotional valence interaction

Results

8 out of 11 behavioral cooperators were matched with being pro-social

8 out of 9 behavioral non-cooperators were classified as pro-selves

Discussion

The reason cooperators have been found to express more positive emotion may be due to their overall increased expressivity of emotion

More important for the valence of the emotion to establish whether the individual is pro-self or pro-social

Discussion

3 rationales for emotional expressivity as a reliable signal of cooperation› Both negative and positive emotions are

difficult to fake› The task of faking emotions becomes much

more formidable when positive and negative emotions must be displayed according to pro-social standards

› Cost of displaying true emotion would be greater for a pro-self, thereby making them more likely to display less emotion overall

Future Directions

Not very generalizable› It has been shown that emotional reactivity

is different in women than in men› Culture would also play a large role in

emotional expressivity› The participants were only interacting with

a computer, and unbeknownst to them a computer was making the proposals for the first two games