A confounding variable is an extraneous variable that is statistically related to (or correlated with) the independent variable. This means that as the independent variable changes, the confounding variable changes along with it. Failing to take a confounding variable into account can lead to a false conclusion that the dependent variables are in a causal relationship with the independent variable. Take, for example, a study that seeks to investigate the relationship between income levels and test scores. Without controlling for other variables, the study finds that higher income correlates with better test scores and concludes that the two must be directly related. This is a flawed conclusion because there are many lurking confounding variables that may influence this supposedly clear-cut relationship. For example, perhaps individuals at one school received better education than those at another school. Without controlling for the confounding variables of education level and quality of education, the relationship between income level and test scores cannot be assumed.