Fiducia TogetherCorrelation and causation
Two things moving together is not one causing the other.
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.
What it is
A correlation is a relationship between two variables — as one changes, so does the other. Causation means one produces the change in the other.
Where it applies
Science, psychology, sociology, geography and maths.
How it works
A correlation can arise from causation in either direction, from a third variable affecting both, or from coincidence.
Only a controlled experiment, or careful design that rules out alternatives, supports a causal claim.
How to use it in your work
State the correlation, then say explicitly that it does not establish cause, then suggest a plausible third variable. That three-part answer scores in every subject that asks it.
On a scatter graph, describe strength and direction — strong positive, weak negative — not just 'there is a correlation'.
Where to get help
Your teacher and your board's specification and mark scheme.
Where to read more
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.