Lecture 3: Emotions and evolution.
What is the origin of life?
Depends who you ask.
a. Christians in 16 century Europe: Special creation, implies immutable species.
*Fossil record reveals: 1. Species change.
3. Extinction. *thus, species are not immutable.
b. Early evolutionary theories: Lamarck.
Transmutation of species was explained by principle of inheritance of acquired characteristics. (modification of limb occur during an
organism’s life time due to increase or decrease used, and it is passed on to its offspring.
Ex: Weightlifter ▯ will have very strong and muscular babies.
Ex: Tape bird’s eyes to prevent sight ▯its offspring will born blind.
Oversight: soft heredity, phenotype is not always tied in with genotype. Lamarck assumed emotion, appearance, behavior are all tied to
c. Nonevolutionary precursors to Darwin.
i). Charles Lyell.
Addressed the problem with Earth’s age, by looking at layers of the earth.
Found that species change but it occur very gradually, thus if earth is young, there is not enough time to accommodate the changes.
Principles of Geology: Earth is older than originally thought, 100million years not 20003000 years. Thus, there is enough time for species to
English political economist. “Population growth rate” > “Food growth rate”. *Struggle for existence. Nature favor the fittest organisms.
*Fitness: best adapted to environment (physical, emotional, behavioral characteristics).
d. Darwin and the voyage of the Beagle.
Observed: there are differences within a specie. Ex: Finches with different beak sizes. Due to different dominate food sources on different
islands (hard vs. tender food).
Natural selection: results from.
1. Within species competition.
Number vs. the resources. Ex: Mate, food, shelter.
2. Heritable variations.
Phenotype tied to genotype.
3. Conditions that differentially favor these variations.
Eg. 1. Peppered moths—physical characteristic, black spot moth is favored after the industrial revolution).
Eg.2. Phototropism –Emotionality/psychological. Moths that likes light, it is a preference for light that is not required to live, thus this is
a psychological characteristic.
Natural selection: making it to sexual maturity (basic survival) ▯low key and not stand out to avoid predators.
sexual prowess (different); Sexual selection—may value traits that endanger basic survival. ▯bright color that attracts mates, also predators.
selfpreservation (NS)selfpropagation (SS).
*Can have interference. Ex: huge bright colored crowns can attract more mate, but may also attract predators.
Given the two pressures, we can ask:
Which behaviors and emotions
Help us survive?
Help us reproduce?
Help us pass our genes to the next generation? *Direct vs. indirect distinctions.
Direct: Produce offspring, directly passing genes along.
Indirect: helping with the kin (offspring of siblings, ex. Cousins, nephews).
To ask the questions, we presume that emotions serve functions:
àOrientation: help us figure out a problem when it occurs.
àorganizing: prepare our body for action. Ex: adrenaline…
àInteracting: help us bond with others, rear our offspring, be protective, foster social network, increase our chances of reproductive and parenting
Darwin’s study of emotional expressions.
The expression of emotions in man and animals.
Found that: actors express very obvious, exaggerated emotions, the mentally illed express spontaneous emotions.
(How are emotions expressed in the face? What noises do animal make when emotional?)
Expression = face + vocalizations + body (tension, posture) + movements.
Darwin and emotional expressions as adaptations.
Emotional expression: an action that used to directly aid with survival.
Ex: cat’s ears, wolves mouthing.
AND – at that time performed in conjunction with felt emotion.
Ex: anger, happiness, gratitude.
Emotion expression is an intention movement, it suggests what actions may follow.
Ex: Cat hiss ▯may be violence, dog mouthing, showing submission.
As such, emotional expressions may save organism from carrying out elaborate suite of actions themselves (expression is a better survival
Eventually, expression occurs even in situations where the action is Useless or Unnecessary.
Thus, can communicate intention (internal state) with emotions, without actually doing the behavior. This can physically protect the body.
Eventually, expressing it can become involuntary.
Darwin, Antithesis and Overflows
Antithesis principle: Distinct signals of anger behaviors are different from what oppose it.
*Approach is the opposite of avoid, with very distinct signals.
Overflows: puzzling gestures, vocalizations. With no function but are release of pentup energy.
Criticisms of Darwin
Overcomplicating, ascribe human quality (emotions) to animals.
The explanation used a lot of story, nonexperimental.
Even so, wealth of modern evidence supports Darwin.
a. Facial expression research: crosscultural and crossspecies. Also with children.(universal).
*The 6 basic emotion expressions: anger, fear, disgust, sad, happy, surprise.
*Thus, emotion is innate and not acquired. (nature, not nurture drives emotional expression). Emotional expressions are a product of
evolutionary past, not immediate environment or socialization.