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Marlow Works

AP Psychology / Biological Bases of Behavior

Lesson

Correlation is not causation

A research habit for every unit.

Explanation

Psychology students should distinguish between correlation and causation. A correlation means two variables are related; it does not by itself show that one variable causes the other.

Practice

Original Marlow Works items. Check the answer explanation after you try.

1 of 1Biological Bases of Behavior · medium · multiple choice

A medication blocks reuptake of a neurotransmitter in the synapse. What is the most likely immediate effect?

Original Marlow Works item — not a College Board question.

Take your time—this is practice, not a test.

Answer explanation

Researchers find that students who sleep more tend to perform better on memory tests. Why can't they conclude from a simple correlation that more sleep causes better memory?

Answer. Other variables may influence both sleep and test performance. A controlled experiment would be needed to make a stronger causal claim.

A correlation shows a relationship, not a cause. Confounding variables can explain both sides of the pattern.

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Related resources

External links with reuse status. Marlow Works is independent and does not copy restricted exam or textbook material.

  • Official / link only

    AP Psychology course page

    Official five-unit framework and science practices.

    College Board · All rights reserved · accessed 2026-10-01

    Open source

  • Reference only — do not copy

    OpenStax Psychology 2e

    Useful psychology background, but current publisher terms restrict commercial reuse and AI ingestion.

    OpenStax · CC BY-NC-SA 4.0 with additional restrictions · accessed 2026-10-01

    Link only. Do not republish or ingest this book.

    Open source