Question

The most common abuse of correlation in studies is to confuse the concepts of correlation with those of causation.

Good SAT scores do not cause good college grades, for example. Rather, there are other variables, such as good study habits and motivation, that contribute to both. Find an example of an article that confuses correlation and causation.

Discuss other variables that could contribute to the relationship between the variables.

Answer 1

Vending machines in Schools and obesity (Thing A causes Thing X causes Thing Y which then causes Thing B): One obvious cause of obesity is eating extra junk food. One obvious source of extra junk food is vending machines. One obvious place to find vending machines is in many schools. So remove vending machines from schools and reduce obesity, right?

No, sadly, not that easy.  In a longitudinal study that surprised even the authors, it was found that kids who moved from schools without vending machines to those with vending machines don’t gain weight. What’s interesting is that you can find a correlation between kids who were overweight and eating food from vending machines, but it turns out the causal relationship is convoluted enough that removing the vending machines don’t actually fix the original endpoint.

there are other variables that are a cause of obesity.

overeating is driven by various other biological factors like genetics and hormones.