PSYC18—Chapter 2 Notes 1
Evolution of Emotions
•A piece of Darwin’s evidence was the similarly of human emotional expressions to
those of lower animals
oArgued that human emotional expressions have some primitive aspects
oDarwin’s theory of evolution
Elements of an evolutionary approach to emotions
•3 parts that drives evolution
Animals and plants produce more offspring than necessary merely to
Each off spring is somewhat different than others , and differences are
passed on by heredity
Characteristics that allow the individual to be adapted to the
environment are selected for
•At the core of natural selection
•The physical and social environment in which humans evolved, determined whether
or not individuals survived and reproduced.
• To survive the individual need to find food and water. Our thermoregulation system,
our fight and flight response etc. developed from selection pressures.
•Darwin did not acknowledge hereditary elements.
oNow we know genes are passed on from one generation to another
•Two kinds of sexual selection pressure determines who reproduces:
Occurs within a sex access to mates. Usually most pronounced among
Stags lock horns and engage in ritualized, at times violent battles to
find out who is dominant and gains access to mates.
He status dynamics of young men –the banter, teasing, playful
wrestling and tests of strength- serve a similar function
•To determine who rises in status and who will have more
access to young women.
The process by which one sex selects specific kinds of traits in the
Women choose men with higher status.
•Social status affects the amount of resources one has and more
resources will benefit future offspring.
Males seek out mates who are fertile and show for youth and beauty –
full lips, youthful skin, an hourglass figure etc—are physical signs of
optimal reproductive age.
•Our capacity to cooperate Is a powerful determinant of who reproduces and who
•Are genetically based traits that allow the organism to respond well to specific
selection pressures and to survive and reproduce.
oExamples: table 2.1, page 36
oOur distaste for bitter foods helps us avoid these toxins
oWomen are particularly sensitive to bitter tastes and smells during their first
trimester of pregnancy morning sickness may be a part of a mechanism to
avoid intake of certain toxins that may harm the fetus.
•Humans look for mates that show signs of fertility and reproductive readiness.
PSYC18—Chapter 2 Notes 3
oEg. People tend to look for mates with symmetrical faces (more extreme,
disfiguration), it guides us towards mates who have been raised in healthy
•Human infants require a lot of care until the age of viability
•Not all human traits or behaviors are adaptations.
oEg. Snoring, leg jiggles, etc, serve no apparent purpose in evolution, it is a
•You should not conclude that all, or even most, human traits emerged de novo, to
meet survival-and reproduction related problems and opportunities.
•Evolution is a tinker, and often endows old anatomical and behavioral features with
oA trait that acquires a new function like this is called an exaptation.
Eg. Animals reflex when startled, they reflex their ears. Its original
function was to protect their ears, but it is now seen as being friendly.
In humans, raising eyebrows is seen when meeting someone or
•It is probably human universal.
•Natural selection is based on genetic variation, and selects for genetically based
traits that help certain individuals meet selection pressures.
oGenes provide potentialities for behavior
Emotions serve functions
•Idea of function: human traits solve survival- and reproduction-related problems,
and help individuals take advantages of opportunities.
•Emotions serve functions – only recently accepted in western thought.
oIt was more typical to portray emotions as disruptive and harmful influences
resulting in destructive behavior, to be mastered by rational thought.
oTend to describe emotions in terms of functions in ways that increase the
chances of survival and reproduction.
Evolution of emotions: a piece of darwin"s evidence was the similarly of human emotional expressions to those of lower animals, argued that human emotional expressions have some primitive aspects, darwin"s theory of evolution. animals and plants produce more offspring than necessary merely to reproduce themselves: variation: each off spring is somewhat different than others , and differences are passed on by heredity: natural selection: characteristics that allow the individual to be adapted to the environment are selected for. Selection pressures: at the core of natural selection, the physical and social environment in which humans evolved, determined whether or not individuals survived and reproduced. To survive the individual need to find food and water. occurs within a sex access to mates. stags lock horns and engage in ritualized, at times violent battles to find out who is dominant and gains access to mates.