Correlation does not imply causation is a fallacy where two things that correlate are mistaken to be in a cause and effect relationship. There might or might not be a causal relationship present. If there is a cause and effect relationship it might be reversed or there might be no causal relationship at all among the subjects.

Correlation Does Not Imply Causation Example

A very famous example of this is air conditioning and crime. It was noted in a study that crime rose as air conditioning use increased. However, air conditioning was not the cause of the crime. What was really happening was that hot weather caused more people to go outside thus increasing human interaction and possibility for crimes to be committed. This was correlation where two things ‘crime’ and ‘air conditioning’ were both effects of hot weather rather than each other.

Correlation vs Causation Structures

When examining subjects and correlation vs causation there are several possibilities for relations between subjects:

A is correlated with B
A is believed to cause B
Reality: B causes A (reversed actuality)

A is correlated with B
A is believed to cause B
Reality: C causes B (third cause)

A is correlated with B
A is believed to cause B
Reality: A causes B (actual causation)