Suppose you are given data from a survey showing the IQ of each person interviewed and the IQ of his or her mother. That is all the information that you have. Your boss has asked you to put together a report showing the relationship between these two variables. What could you present and why?

As you think about this week's question, remember that there is a difference between correlation and causation.Whenever we have a strong correlation, it's tempting to try to explain it by imagining the independent variable hascausedthe response to the change.Humans are like that; we tend to see causes and effects in everything.

Scatter plots and correlation coefficientsneverprove causation.That's one reason it took so long for the US Surgeon General to get warning labels on cigarettes.Although there was plenty of evidence that increased smoking wasassociatedwith increased levels of lung cancer, it took years to provide evidence that smoking actuallycauseslung cancer.