Describes a causal relationship between two events or phenomena, i.e. that one is caused by the other.
The steeper angle of the sun’s rays in summer causes higher temperatures at that time of year.
It is important to distinguish the concept of causality from that of correlation, which refers to a common occurrence of the events or phenomena but does not imply a causal relationship.
Note: The term “causality” describes a complex concept that has been the subject of controversy in philosophy and science for millennia. It would go far beyond the scope and possibilities of this site to present the topic or the controversies in a way that is fair to their complexities. The following can therefore not be more than a first approach to the subject.
As a general rule, when phenomena 𝚨 and 𝐁 occur in correlation (i.e. either simultaneously or consecutively), the following possibilities must be considered:
- 𝚨 causes 𝐁 (direct causal relationship).
- 𝐁 causes 𝚨 (reverse causal relationship).
- A third event 𝐂 causes both 𝚨 and 𝐁 (external causal relationship).
- 𝚨 causes other events: e.g. 𝐂, 𝐃, etc, which in turn cause 𝐁 (indirect causal relationship).
- 𝚨 and 𝐁 are not causally connected, but only occur together by chance (☞ spurious correlation).
The fact that 𝚨 and 𝐁 correlate with each other, i.e. that they regularly occur together, is not sufficient to postulate a causal relationship.
Remember: Correlation does not imply causality!
- Causality on Wikipedia