AP Psychology Lesson: Nature, Nurture, and Evolution

Unit: Biological Bases of Behavior | Lesson: 1 of 6 | Topic: Nature, Nurture, and Evolution: How Genes and Environment Shape Behavior
AP Exam Weighting: 15–25%
Instructions: Complete this handout during class by filling in the blanks and answering questions. All information needed is provided or will be researched in class. This lesson prepares you for the AP Psychology exam by exploring how genes, environment, and evolution interact to influence behavior, a foundational concept for understanding the biological basis of psychology. Use the provided spaces to write your answers clearly, focusing on applying concepts critically.

Warm-Up

Purpose: Get you thinking about how biology and environment shape behavior.
Questions:

1. Why might siblings raised in the same home have very different personalities?

2. Can you think of a behavior you have that might come from your family’s traits or your upbringing?
   Your Answers: Write a short response (1–2 sentences) for each question.

3. __________________________________________________________________

4. __________________________________________________________________

Key Concepts

Instructions: Read the information below and answer the questions to learn core AP concepts.
Content: Behavior results from the complex interplay of genes (inherited traits encoded in DNA), environment (social, cultural, and experiential influences), and evolution (adaptations that aided ancestral survival). Heritability estimates the proportion of a trait’s variation in a population due to genetics (e.g., intelligence is ~50% heritable, meaning half its variation is genetic). Epigenetics describes how environmental factors, like stress or nutrition, alter gene expression without changing DNA (e.g., trauma may increase anxiety gene activity). Natural selection, a core evolutionary mechanism, favors traits enhancing survival and reproduction (e.g., fear of predators like snakes). Behavioral genetics examines how genes and environment contribute to behaviors like aggression or shyness. The nature-nurture debate explores the relative contributions of biology (nature) versus experience (nurture), with modern psychology emphasizing their interaction. Example: Identical twins raised apart may share traits like risk-taking due to genes, but differ in confidence due to different social environments. Another example: Evolutionary preference for high-calorie foods aided survival in scarce environments, but modern diets shape obesity rates. Cultural norms, like collectivism in some societies, further influence how genetic traits are expressed (e.g., social behaviors).

1. Define heritability: _______________________________

2. Define epigenetics: _______________________________

3. Define natural selection: _______________________________

4. Explain how genes influence a behavior, using a specific example:
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5. Explain how environment influences a behavior, using a different example:
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6. How does behavioral genetics contribute to understanding the nature-nurture debate?
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7. Why might an evolutionary trait like fear of heights vary in expression across cultures?
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8. How might epigenetics explain differences in stress responses among siblings?
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Guided Activity

Instructions: Work in pairs to complete the two tasks below. Write your answers and be prepared to share one key point from each task with the class.
Task 1: Scenario Analysis: Scenario: A set of identical twins raised in different countries both excel at music, but one is highly competitive while the other is collaborative. Analyze how genes, environment, and evolution might explain these traits. For example, consider whether musical ability has a genetic basis, how cultural values shape competitiveness, and why creativity might have evolved.
Your Response for Task 1: Explain the role of genes, environment, and evolution in these traits.
__________________________________________________________________
Class Share for Task 1: [Note one point you’ll share.]
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Task 2: Case Application: Imagine a high school student who is naturally gifted at problem-solving but struggles with anxiety in social settings. Apply the concepts of heritability, epigenetics, and natural selection to explain their abilities and challenges. For example, evaluate whether problem-solving is heritable, how social environment might trigger anxiety, and why anxiety might have an evolutionary basis.
Your Response for Task 2: Apply the concepts to explain the student’s traits.
__________________________________________________________________
Class Share for Task 2: 
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Do Class Assignment

AP Exam Practice

Instructions: Answer the question below. We’ll review answers as a class to learn exam strategies.
Free-Response Question (FRQ):
Explain how genes, environment, and evolution interact to influence a specific behavior (e.g., aggression, intelligence, or fear). Provide one example for each factor (genes, environment, evolution) and analyze how they interact to shape the behavior.
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Closure

Instructions: Write a brief summary of two or three key ideas you learned today about how genes, environment, or evolution influence behavior.
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Extended Practice

Instructions: Complete the tasks below based on today’s lesson to reinforce AP skills.

1. Review your answers from this lesson

2. Write a detailed paragraph (5–7 sentences) applying today’s topic to a real-life behavior (e.g., why you or someone you know might be shy, outgoing, or good at a specific skill). Include references to genes, environment, and evolution, and explain their interaction.
   __________________________________________________________________

3. Find a short article or study on nature vs. nurture (e.g., via apa.org) and write 2–3 sentences summarizing its relevance to today’s lesson. Cite the source (e.g., website or article title).
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