Evolutionary Evolutionary PsychologyPsychology

Chapter 4, Lecture 2Chapter 4, Lecture 2

“The typical genetic difference between twoIcelandic villagers or between two Kenyans ismuch greater than the average differencebetween the two groups.” - David Myers

Evolutionary Psychology: Understanding Human Nature

Evolutionary psychology studies why we as humans are alike. In

particular, it studies the evolution of behavior and mind using principles

of natural selection.

First, complete handout First, complete handout 4.4…4.4…

Natural Selection

Natural selection is an evolutionary process through which adaptive traits are passed on to ongoing generations

because these traits help animals survive and reproduce.

Artificial SelectionBiologists like Belyaev and Trut (1999)

were able to artificially rear and domesticate wild foxes, selecting them

for friendly traits.

Any trait that is favored naturally or artificiallyspreads to future generations.

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Human Traits

A number of human traits have been identified as a result of pressures

afforded by natural selection.

Why do infants fear strangers when they become mobile?

Why do people fear spiders and snakes and not electricity and guns?

How are men and women alike? How and why do men’s and women’s sexuality differ?

Human Sexuality

Males and females, to a large extent, behave and think similarly. Differences in

sexes arise in regards to reproductive behaviors.

Gender Differences in Sexuality

Question (summarized) MaleFema

le

Casual sex 58% 34%

Sex for affection 25% 48%

Think about sex everyday 54% 19%

Natural Selection & Mating Preferences

Natural selection has caused males to send their genes into the future by mating with multiple females since males have lower

costs involved. However, females select one mature and caring male because of the higher costs involved with pregnancy and nursing.

Consider the “Coolidge Effect”Consider the “Coolidge Effect”

In certain animal species, a male that has become sexually exhausted from repeated copulation with the same female will demonstrate renewed vigor if presented with a succession of new females. The phenomenon is called the Coolidge effect because of a reported verbal exchange between President and Mrs. Calvin Coolidge.

Consider the “Coolidge Effect”Consider the “Coolidge Effect”

While touring a farm, Mrs. Coolidge is said to have been impressed by the untiring sexual activity of one rooster. “You might point that out to Mr. Coolidge,” she told the farmer. Hearing her remark, the president asked the farmer whether a different hen was involved each time. When informed that indeed this was the case, he replied, “You might point that out to Mrs. Coolidge.”

Consider the “Coolidge Effect”Consider the “Coolidge Effect”

So what is the evolutionary So what is the evolutionary explanation for the Coolidge explanation for the Coolidge

effect???effect???

Mating Preferences

Males look for youthful appearing females in order to pass their genes into the future.

Females, on the other hand, look for maturity, dominance, affluence and

boldness in males.

Data based on 37 cultures.

CharacteristicsPreferred by Males

CharacteristicsPreferred by Females

1. Kindness & understanding2. Intelligence3. Physical attractiveness4. Exciting personality5. Good health6. Adaptability7. Creativity8. Desire for children9. College graduate10. Good heredity11. Good earning capacity12. Good housekeeper13. Religious orientation

1. Kindness & understanding2. Intelligence3. Exciting personality4. Good health5. Adaptability6. Physical attractiveness7. Creativity8. Good earning capacity9. College graduate10. Desire for children11. Good heredity12. Good housekeeper13. Religious orientation

Critiquing the Evolutionary Perspective

Evolutionary psychologists take a behavior and work backward to explain it in terms of natural selection.

Evolutionary psychology proposes genetic determinism and undercuts morality in establishing society.

Where genders are unequal, gender preferences are wide, but when they are closely equal, preferences

narrow down.

Evolutionary Psychologists Reply

Evolutionary psychologists argue that we need to test behaviors that expound evolutionary principles.

Evolutionary psychologists remind us how we have adapted, but do not dictate how we ought to be.

Males and females are more alike than different, and if we study these differences we can establish their

causes.

“Darwinian Grandparenting”Get out your journal, and reflect on your personalrelationship with your grandparents.

Rate your emotional closeness from 0 = cold ornegative Feelings to 10 = warm or positive feelings toeach biological grandparent (identify them as mother’smother, mother’s father, father’s mother, and father’sfather).

Next, use those ratings to rank-order, from 1 (closest) to4 (most distant), each grandparent in terms of closeness.

Offer any important explanations for any of yournumerical answers…

HomeworkRead p.149-153

“As mobile gene machines, we are designed toprefer whatever worked for our ancestors intheir environments.” - David Myers

“…the study of how we came to be need notdictate how we ought to be. Understanding ourpropensities sometimes helps us overcomethem.” - David Myers