When people talk about equality, diversity and unconscious bias, they often make the assumption that one thing is caused by another. It may well be, but sometimes there is a correlation between two things, but no causal link i.e. one thing did not cause the other.
You may have heard someone say, ‘correlation does not cause/mean causation’, this is what we’ll look at here.
Correlation
Correlation tells us how strongly two things are related and change together.
Look at this example. As the sales of ice creams increases in Sunnyville so does the sale of sunglasses, and when the sales of ice cream go down, the sale of sunglasses does too.
In other words, there’s a strong correlation (co-relation) between the two.
Sunnyville is a seaside town and as the sales of ice creams goes up, so does the number of shark attacks.
Although there is a strong correlation between the two, one doesn’t cause the other. There’s no causal link.
Causal link
Sometimes when there’s a strong correlation between two things, there’s a temptation to say that one causes the other. However, it’s very difficult to prove a causal link as there are often other factors involved.
For example, in Sunnyville’s case there could be more shark attacks in summer:
- when the water is warmer
- when more people go swimming
- …
and also, at the same time, sales of ice creams and sunglasses increase.
The relationship between diversity and performance
It’s often said that there is a link between diversity in an organisation and the organisation’s performance. An important report in this are is the McKinsey & Company report (Diversity Matters 2015).
The report showed that the companies in the top quartile for gender diversity and racial/ethnic diversity were more likely to have financial returns above their national industry median by the following amounts:
- gender diversity 15%
- racial/ethnic diversity 35%.
However, the report says:
“This correlation does not prove that the relationship is causal—that greater gender and ethnic diversity in corporate leadership automatically translates into more profit—but rather indicates that companies that commit to diverse leadership are more successful.”
The relationship is consistent and statistically significant, but it has not been proven that one causes the other.