Correlation is not causation:
| Definition | Example |
| When a correlation found between two variables is presumed to demonstrate a causal relationship | Children who eat breakfast have higher grades, so eating breakfast causes higher grades. |
| Also known as: cum hoc ergo propter hoc | |
| Notes | |
| There may be a 3rd factor causing both higher grades and eating breakfast such as more responsible and loving parents who help children with homework as well as make sure they eat breakfast. While correlation is evidence for causation, especially when other factors have been controlled for, moving from correlation to causation demands a rigorous scientific protocol. | |
Case Study One
It has been argued that religious belief is what has made America economically strong, and, conversely, that a lack of religious belief is what keeps crime rates so low in Japan. Neither claim is warranted if merely based on the coexistence of the 2 phenomena cited. There may well be other causal factors.
Case Study Two
People who eat diet food seem to be heavier on average than those who don’t. What can we say about any possible arrow of causation between diet food and heavier people? Is there causation? Which direction is the causation? Is it necessarily uni-directional?
Case Study Three
It has been claimed that people with red cars drive faster than people with blue cars. What is it about the color red that causes faster driving. Or is it that more aggressive personalities have an affection for both red and speed. Or is it possible that the data used to conclude that drivers of red cars drive faster than blue cars is taken from a biased source? Do police target red cars more than they do blue cars, thereby skewing the data?
Keep in mind that a fallacious argument does not entail an erroneous position.
Logfall - Logical Fallacies 