Module 15 — Evolutionary Psychology Notes

Natural Selection and Evolutionary Psychology

• Darwin’s principles guide evolutionary psychologists in understanding what makes humans so much alike.

What is Natural Selection?

• The principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations.

What is a Mutation?

• A random error in gene replication that leads to a change.

Darwin’s Basic Principles

• Organisms’ varied offspring compete for survival.
• Certain biological and behavioral variations increase organisms’ survival chances in their particular environment.
• Offspring that survive are more likely to pass their genes to the next generation.
• Over time population characteristics may change.

Foxes and Domestication (An Example)

• Researchers Belyaev and Trut selectively bred the tamest foxes.
• After 30 generations (≈ 40 years) they produced “docile, eager to please, domesticated” animals.
• Conclusion: psychological traits can be selected as well as physical traits.
• Generational note:$30 \text{ generations} \quad (\approx 40 \text{ years})$.

Naturally Occurring Selection and Brain Wiring

• Our historical genes give us a great capacity to learn and to adapt to life in varied environments, from the tundra to the jungle.
• Genes and experience together wire the brain.
• Our adaptive flexibility in responding to different environments contributes to our fitness—our ability to survive and reproduce.

Male–Female Differences in Sexuality and Mating Preferences

• Males:
  • May be more likely to initiate sexual activity.
  • May perceive women’s friendliness as sexual interest.
• Females:
  • Tendency toward tall men with slim waists and broad shoulders.
  • May prefer men who are mature, dominant and bold.

Social Scripts

• A culturally modeled guide for how to act in various situations.
• Example: restaurant script—enter, take a seat, read a menu, order, eat, pay the bill, leave.
• Social scripts also provide indications of how men and women, elderly and young, etc., might act in a society.

Criticism of the Evolutionary Perspective on Sexuality

• Start with the effect and work backward to explain what happened.
• Try to explain today’s behavior with decisions made thousands of years ago.
• There are social consequences to accepting evolutionary explanations.

Evolutionary Psychologists’ Responses to Criticism

• Much of who we are is NOT hardwired; genes are NOT destiny.
• Men and women are far more alike than different.
• Some traits and behaviors are hard to explain in terms of natural selection.

More on the Evolutionary Perspective: Responses

• Evolutionary psychologists agree that genes are not destiny, and respond that understanding our predispositions can help us overcome them.
• They cite the value of testable predictions based on evolutionary principles, which is the scientific goal of evolutionary psychology.

Biopsychosocial Approach to Development

• Genes, environment and our culture all combine to influence our development.

Quick Practice Question: What Would You Answer?

• The interaction of biological influences, psychological influences, and social-cultural influences on our behavior is known as:
  • A. evolutionary psychology.
  • B. epigenetics.
  • C. the biopsychosocial approach.
  • D. consciousness.
  • E. natural selection.

Learning Target 15-1 Review

• Describe evolutionary psychologists’ use of natural selection to explain behavior tendencies.
• Evolutionary psychologists consider how natural selection results in traits being passed on to future generations.
• Some genetic variations arise from mutations; others from new gene combinations at conception.
• Charles Darwin’s theory of evolution anticipated today’s application of evolutionary principles in psychology.

Learning Target 15-2 Review: Male–Female Differences in Sexuality and Mating Preferences

• Women tend to be more selective than men when choosing sexual partners.
• Evolutionary psychologists reason that:
  • Men’s attraction to multiple healthy, fertile-appearing partners increases their chances of spreading their genes widely.
  • Women search for mature mates who will share child rearing with them, increasing the odds of the offspring’s survival.

Learning Target 15-3 Review: Criticisms and Responses

• Critics argue that evolutionary explanations:
  • Start with an effect and work backward to an explanation.
  • Do not recognize social and cultural influences.
  • Absolve people from taking responsibility for their sexual behavior.
• Genes are not destiny.

Learning Target 15-3 Review cont.: Deeper Responses

• Evolutionary psychologists agree that genes are not destiny, and respond that understanding predispositions can help us overcome them.
• They also cite the value of testable predictions based on evolutionary principles, which is the scientific goal of evolutionary psychology.

Learning Target 15-4 Review: Biopsychosocial Approach to Development

• Biological: shared human genome; individual variations; prenatal environment; and sex-related genes, hormones, and physiology.
• Psychological: gene–environment interactions; effect of early experiences on neural networks; responses evoked by our own characteristics; and personal beliefs, feelings, and expectations.
• Social-cultural: parental and peer influences, cultural traditions and values, and cultural gender norms.