# Correlation vs. Causation: What's the Difference?

Edited by Aimie Carlson || By Janet White || Published on November 28, 2023
Correlation indicates a relationship between two variables without implying one causes the other. Causation means one variable directly impacts or causes changes in another.

## Key Differences

Correlation refers to a mutual relationship or connection between two or more things. Causation, on the other hand, implies that a change in one variable is responsible for a change in another.
Correlation can be positive, negative, or zero, suggesting different types of relationships. Causation, however, asserts a direct cause-and-effect relationship where one event is the consequence of another.
Observing a correlation between two variables doesn’t automatically mean there's a causal relationship. Without further investigation, assuming causation can lead to false conclusions.
It's possible for two variables to have a strong correlation because they're both influenced by a third variable, not because one causes the other. Causation requires more stringent evidence, typically through controlled experiments.
Simply put, while correlation can hint at a relationship between two variables, causation explicitly states that one variable is the reason for the change in another.

## Comparison Chart

### Definition

A measure of relationship between two variables.
A relationship where change in one causes change in another.

### Implication

Does not imply direction or causality.
Implies a direct cause and effect.

### Evidence Requirement

Requires statistical analysis.
Requires rigorous experimentation or evidence.

### Dependency

Can be due to third variables or chance.
Assumes direct dependency without third variables.

### Interpretation

"X and Y move together."
"X causes Y."

## Correlation and Causation Definitions

#### Correlation

Mutual relation of two or more things.
There's a correlation between ice cream sales and hot weather.

#### Causation

The principle that everything has a cause or reason.
Philosophers often debate the concept of causation in the universe.

#### Correlation

An association or similarity between two variables.
There's a correlation between a person's height and shoe size.

#### Causation

The act or process of causing something to happen or exist.
The causation of the fire was determined to be faulty wiring.

#### Correlation

A synchronized movement or trend between two variables.
The correlation between stock market performance and consumer confidence is often discussed.

#### Causation

A relationship where one event or situation brings about another.
There's clear causation between reckless driving and car accidents.

#### Correlation

A connection or link between two things based on co-occurrence or pattern.
The correlation between higher education and higher income is well-known.

#### Causation

An agency or circumstance that leads to a result.
The court had to determine the causation of the property damage.

#### Correlation

A relationship or connection between two things based on co-occurrence or pattern of change
A correlation between drug abuse and crime.

#### Causation

The act or process of causing.

#### Correlation

(Statistics) The tendency for two values or variables to change together, in either the same or opposite way
As cigarette smoking increases, so does the incidence of lung cancer, indicating a positive correlation.

A cause.

#### Correlation

An act of correlating or the condition of being correlated.

Causality.

#### Correlation

A reciprocal, parallel or complementary relationship between two or more comparable objects.

#### Causation

The act of causing.

#### Correlation

(statistics) One of the several measures of the linear statistical relationship between two random variables, indicating both the strength and direction of the relationship.

#### Causation

The act or agency by which an effect is produced.

#### Correlation

(algebra) An isomorphism from a projective space to the dual of a projective space, often to the dual of itself.

#### Causation

Cause and effect, considered as a system.

#### Correlation

Reciprocal relation; corresponding similarity or parallelism of relation or law; capacity of being converted into, or of giving place to, one another, under certain conditions; as, the correlation of forces, or of zymotic diseases.

#### Causation

The act of causing; also the act or agency by which an effect is produced.
The kind of causation by which vision is produced.

#### Correlation

A reciprocal relation between two or more things

#### Causation

The act of causing something to happen

#### Correlation

A statistic representing how closely two variables co-vary; it can vary from -1 (perfect negative correlation) through 0 (no correlation) to +1 (perfect positive correlation);
What is the correlation between those two variables?

#### Causation

The factor or agent that produces an effect.
In the study, they looked for the causation of the disease outbreak.

#### Correlation

A statistical relation between two or more variables such that systematic changes in the value of one variable are accompanied by systematic changes in the other

#### Correlation

A statistical measure expressing the extent of interdependence of variable quantities.
The correlation between smoking and lung disease is strong.

## FAQs

#### Why is it dangerous to assume Causation from Correlation?

Assuming causation without proper evidence can lead to incorrect conclusions and misguided actions.

#### Are Correlation coefficients an indicator of Causation?

No, correlation coefficients measure the strength and direction of a linear relationship, not causation.

#### Can Correlation imply Causation?

No, correlation does not imply causation, though it might suggest a potential causal relationship.

#### What is Correlation?

Correlation is a statistical measure indicating the extent to which two variables change in relation to each other.

#### How is Causation established?

Causation is often established through controlled experiments or rigorous observational studies.

#### Can Causation exist in the absence of Correlation?

Yes, especially if other factors mask or offset the causal effect.

#### What is Causation?

Causation refers to a relationship where a change in one variable directly results in a change in another.

#### Can two variables have a Correlation without Causation?

Yes, two variables can be correlated without one causing the other.

#### What's an example of Correlation without Causation?

An example is the correlation between ice cream sales and drownings, both increase in summer but one doesn't cause the other.

#### What does a Correlation of zero mean?

A correlation of zero means there's no linear relationship between the two variables.

#### Is "cause and effect" the same as Causation?

Yes, "cause and effect" is a common way to describe a causal relationship.

#### Can Correlation be negative?

Yes, if one variable increases while the other decreases, they have a negative correlation.

#### Are there tests to determine Causation?

Yes, experimental designs, especially randomized controlled trials, are used to infer causation.

#### Can Correlation be used as preliminary evidence for Causation?

Yes, a strong correlation can be an initial indicator, but further research is required to determine causation.

#### What's a real-world example where Correlation and Causation are confused?

The correlation between a rooster crowing and sunrise; the rooster doesn't cause the sun to rise.

#### Can two variables be correlated and have a causal relationship?

Yes, two variables can be both correlated and have a causal relationship.

#### How can one differentiate between Correlation and Causation?

One can differentiate by critically evaluating the evidence, considering other variables, and looking for experimental or observational data that supports causation.

#### Why is understanding the difference between Correlation and Causation important?

Understanding the difference helps avoid drawing incorrect conclusions and making uninformed decisions.

#### Does Causation require a correlation?

Not necessarily. There can be causation without correlation if other variables or factors mask the causal relationship.

#### How do third variables affect Correlation and Causation?

A third variable can create a false impression of correlation, or hide a true causal relationship.