Correlation vs Causation
📋 What it is
Correlation means two things move together; causation means one actually CAUSES the other — they’re not the same.
🗣️ Coach says
The most important warning in all of data: correlation is NOT causation. Ice-cream sales and shark attacks rise together — but ice cream doesn’t cause sharks; hot weather causes both. Always ask if a hidden third cause is at work.
🧠 Memory hook
Move together ≠ one causes the other. Ask: "is there a hidden third cause?" (Hot weather → ice cream AND swimming.)
😂 Giggle
What did the x-axis say to the y-axis?
"Let's meet in the middle and plot something together!"
😲 Whoa!
There’s a real correlation between the number of movies a certain actor appears in and drownings that year — pure coincidence, not cause.
✅ Quick check: Ice-cream sales and drownings both rise in summer. Does ice cream cause drownings?
Say your answer out loud first — then reveal.
No — hot weather is a hidden cause of both; it’s correlation, not causation.
A third factor (heat) drives both, so they correlate without one causing the other.
🪄 Trick question: Two things are strongly correlated. Can you conclude one causes the other?
Careful — think it through, then reveal.
No — correlation alone never proves causation; you need more evidence.
A hidden variable or coincidence can create correlation without any causal link.
🧪 Try it! (2 minutes)
Find two things that rise together but don’t cause each other. Name the hidden third cause.