Can correlation show causality?

Can correlation show causality?//Correlation does not equal to causation.

Correlation refers to the departure of 2 variables from independence.
In psychology, Correlation is defined as a statistical measurement of the relationship between two variables. Correlation is computed/calculated into the correlation coefficient, which ranges between -1 and +1.

Relationship means there is an association between two variables. Positive correlation is as one variable increases, the other also increases, and vice versa. Positive correlation is represented by Correlation Coefficients greater than 0. (from any value > 0 to 1, the closer to (+)1 indicates the stronger correlation). Example of positive correlation could be time spent on revision and exam result; the longer time spent on revision get better results. Negative Correlation is as the amount of one variable increases, the other decreases (and vice versa). Negative correlation is represented by Correlation Coefficients less than 0. (from any value < 0 to -1, the closer to (-)1 indicates the stronger correlation).


Causation/causality is the action of causing or producing; the relationship between the cause and effect.

These two terms sound similar but they are different, Even if two variables are legitimately correlated, there is not necessarily any causal relationship between them. An example is there is a relationship between reading ability and shoe size. If an individual performed such a survey they would find that the larger shoe sizes correlate with better reading ability, but this does not mean large feet cause good reading skills.

Correlation does not imply causation. Correlation is more like suggesting a relationship between the variables whereas causality is talking about the distinct relationship between the variables (= cause and effect). Just because two events correlate does not mean that one has caused the other. The Latin term for such an error is called “non causa pro causa,” which means “non-cause for the cause.” It is important to become more critical.

Is it possible for us to be 100% sure that a correlation between two events indicates a causal relationship? It is IMPOSSIBLE, actually.  The knowledge provided by the scientific method is never 100% certain. Science allows us to remain open to the possibility that new evidence will cause a change in what we already know and believe. However, the scientific methods (correlation coefficient here) can always act as a clue, therefore we can investigate more from that point, and with the stronger evidence and enough information, we can justify concluding a strong correlation between two variables points to a causal relationship.

little back up 😀

An advantage of the correlation method is that we can make predictions about events/things when we know about the correlations. If two variables are correlated, we can predict one based on the other. Just like the predicted grade system in UCAS allow the universities to decide which student to take(give offer)and who to reject.

The disadvantage is that a correlation tells us that the two variables are associated, but we cannot say anything about whether one caused the other. This method does not allow us to come to any conclusions about cause and effect.

Always remember the crucial principle: Correlation is not Causation!

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One Response to Can correlation show causality?

  1. katepsuc7d says:

    i don’t think correlation can show causation. i think this is a major problem with quantitative data and research. i know that the correlation shows a significance, for example there is definately correlation between obesity and heart disease, and although a quantitative report would show us this, it couldn’t tell us why. using the same example most people know the causation between obesity and heart disease because we all know the health problems and stuff… but we can’t simply find this out just by knowing there is a correlation between the two varibles. we would have to expand on the previous work to find out more about the relationship and the causation.

    so, although i don’t think correlation can show causation, i think once a correlation or causation is found then expanding on the research and carrying out more research and the rest will fall into place!

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