A Causal Claim Needs a Mechanism

Lab Brief #4

🎯 Your mission

Understand the idea. Then look for it everywhere.

⚡ The twist

Nature loves to surprise the careful watcher.

What you'll learn

A pattern establishes that something is happening; a mechanism establishes what. Snow depth and heating bills rise together, but the mechanism runs through temperature, which drives both independently. Science therefore treats a causal claim as provisional until somebody can describe the physical process carrying the effect step by step — which is exactly why the carbon dioxide and temperature link is treated as causal: the infrared absorption was measured in a laboratory long before the trend appeared.

Key words

mechanism
The physical process by which one thing causes another, described step by step.
provisional
Accepted for now but open to revision, which is how a causal claim is held until a mechanism is demonstrated.

Make a hypothesis first

Before you start: write down what you think will happen, and why.

Say your guess out loud — then find out if you were right.

Step 1 of 4 · Read

Think about what you just learned: say what "mechanism" and "provisional" mean in your own words before you start.

Step 2 of 4 · Do

Take four correlated pairs and, for each, write either the mechanism connecting them or the third variable that explains both. Rank the four by how confident your explanation makes you and justify the ranking in one sentence each.

Step 3 of 4 · Observe

Record what actually happened, including anything that did not match what you expected.

Step 4 of 4 · Record

Write a conclusion that answers the question this lesson opened with, and state your uncertainty.

Question 1 of 3

Snow depth and heating bills correlate because both are driven by:

How sure are you?😐 maybe

Question 2 of 3

A causal claim is held as provisional until somebody can supply a:

How sure are you?😐 maybe

Question 3 of 3

The carbon dioxide and temperature link is treated as causal partly because the infrared absorption was:

How sure are you?😐 maybe

Mind = blown

🔬 The more you look, the more nature shows you.

Nice work!

You got 0 of 3 right.

Next: Models Are Built to Be Wrong in Known Ways All lessons

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✨ More to explore

🌍 Where you see this in real life: This shows up in your everyday life more than you'd think.

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👨‍👩‍👧 For the dinner table: “What's the most surprising thing you learned today?”

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