Correlation and Causation in Year 12 Mathematics Standard

As the HSC course in Mathematics Standard 2 nears its’ completion at KHS, our 12MS2A2 students furthered their understanding of statistical analysis and bivariate data by digging into the concept of correlation vs causality.

After defining correlation as “things that are related to one another mathematically” and causation as “something that causes another thing to occur”, students were asked to investigate seemingly unrelated variables to conclude whether they are, in fact, correlated.

The five groups investigated:
• Number of pirates and global warming
• Studying ethics and theft
• Bladder control and ability to save money
• Ice-cream sales and murder rates
• Number of Nicholas Cage movies and swimming pool drownings (between 1999 and 2009)

The groups presented their findings using only symbols, numbers and pictures to their class and all came to the conclusion that, surprisingly, the five sets of variable pairs all had varying levels of correlation, but none experienced causality.

The presentations opened up further robust class conversations about famous correlation/causality debates such as the findings of the Donohoe and Levitt study that investigated the links between legalized abortion and crime rates in the United States. The conversations explored the inherent difficulty in considering issues from purely a mathematical viewpoint without considering the ethical issues involved.

The students can be proud of the way they engaged in this investigation and have gained an increased appreciation of the power of mathematics!