correlation

American  

[kawr-uh-ley-shuhn, kor-] / ˌkɔr əˈleɪ ʃən, ˌkɒr- /

especially British, corelation

noun

1. mutual relation of two or more things, parts, etc..

   Studies find a positive correlation between severity of illness and nutritional status of the patients.

   Synonyms:

   interconnection, interrelationship, interdependence, equivalence, parallelism, correspondence, similarity

2. the act of correlating or state of being correlated.

3. Statistics. the degree to which two or more attributes or measurements on the same group of elements show a tendency to vary together.

4. Physiology. the interdependence or reciprocal relations of organs or functions.

5. Geology. the demonstrable equivalence, in age or lithology, of two or more stratigraphic units, as formations or members of such.

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correlation British  

/ ˌkɒrɪˈleɪʃən /

noun

1. a mutual or reciprocal relationship between two or more things

2. the act or process of correlating or the state of being correlated

3. statistics the extent of correspondence between the ordering of two variables. Correlation is positive or direct when two variables move in the same direction and negative or inverse when they move in opposite directions

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Pop Culture

—Pearson correlation coefficient: a value between -1 and +1 that represents the relationship between two variables.

Other Word Forms

• correlational
  adjective
• intercorrelation
  noun
• miscorrelation
  noun
• noncorrelation
  noun

Etymology

Origin of correlation

First recorded in 1555–65; from Medieval Latin: correlātiōn- (stem of correlātiō ); see cor-, relation

Explanation

Correlation is something that scientists are often trying to show––is there a correlation between smoking and poor health or between napping and productivity? How about daily flossing and good grades? Correlation derives from the Latin cor- 'together' and -relatio 'relation'––the word is all about things that go together. But beware: just because a study shows a correlation between two variables, it doesn't mean one necessarily causes the other. There is a significant correlation between going to high school and being a teenager, but that doesn't mean that going to high school causes you to be a teenager.

Example Sentences

The Cboe Implied Three-Month Correlation Index hit close of 11.36 on Thursday, the lowest close since Jan. 30, 2025, according to Dow Jones Market Data.

From MarketWatch • May 17, 2026

"Everyone has heard it a million times, but it bears repeating: Correlation doesn't equal causation," Gennaro said.

From Science Daily • Dec. 14, 2025

But to repeat basic logic: Correlation does not prove causation.

From The Wall Street Journal • Nov. 23, 2025

Correlation is not necessarily causation, but we all have our suspicions.

From Salon • Dec. 16, 2024

In 1918, Fisher published his analysis in a paper entitled “The Correlation between Relatives on the Supposition of Mendelian Inheritance.”

From "The Gene" by Siddhartha Mukherjee

Related Words

• interaction
• interrelationship
• parallel