In hypothesis testing, if a sociologist states, 'If education level increases, then income level will increase,' which variable is the independent variable?

In hypothesis testing, the independent variable is the one that is changed or controlled to test its effects on another variable. In the statement "If education level increases, then income level will increase," the education level is the independent variable because it is what the sociologist is manipulating or examining to see how it affects income. The income level is the dependent variable, as it is the outcome that may change based on the education level. For example, if a sociologist studies a group of people and finds that those with higher education tend to earn more money, they are showing how the independent variable (education) influences the dependent variable (income). Thus, in this hypothesis, education level is the factor that is being tested.