# Ecological correlation

In statistics, an **ecological correlation** (also *spatial correlation*) is a correlation between two variables that are group means, in contrast to a correlation between two variables that describe individuals. For example, one might study the correlation between physical activity and weight among sixth-grade children. A study at the individual level might make use of 100 children, then measure both physical activity and weight; the correlation between the two variables would be at the individual level. By contrast, another study might make use of 100 classes of sixth-grade students, then measure the mean physical activity and the mean weight of each of the 100 classes. A correlation between these group means would be an example of an ecological correlation.

Because a correlation describes the measured strength of a relationship, correlations at the group level can be much higher than those at the individual level. Thinking both are equal is an example of ecological fallacy.[1]

## See also

- General topics

- Ecological regression
- Geographic information science
- Spatial autocorrelation
- Complete spatial randomness
- Modifiable Areal Unit Problem

- Specific applications

## References

- Vogt, W. Paul; Johnson, R. Burke (2011).
*Dictionary of Statistics & Methodology: A Nontechnical Guide for the Social Sciences*. Sage. p. 119. ISBN 978-1-4522-3659-9.