Question

8. Consider again the study looking at the impact of people’s income (middle-class vs. wealthy) and personality (extrovert vs. introvert), on two distinct outcomes (people’s life-satisfaction and health). Now, define the term ‘interaction effect’. Tell me how many interaction effects would this study have? What findings / results would each of the interaction effects describe or pertain to? Be specific?

Answer 1

‘Interaction Effect’ can be defined as the dependence of one independent variable on the value of another independent variable to produce the effect on the dependent variable. Interaction effects are produced when statistical instruments like regression analysis, ANOVA, and factorial designs are used. They are also produced in designed experiments. Interaction effects are produced in more complex researches, with more than one independent variables. Interaction effect is produced when a third variable interferes in the relationship between an independent and a dependent variable. In other words, it can be said that one independent variable interacts with another independent variable to produce an effect on a dependent variable.

In the above-mentioned study, two interaction effects can be produced. The two interacting variables (that is, two or more variables that interact with each other to generate an interaction effect), that is, people’s income (middle-class vs. wealthy) and personality (extrovert vs. introvert) interact with each other to generate an interaction effect on the response or dependent variable, namely people’s life-satisfaction. The same two interacting variables interact with each other to generate an interaction effect on the response or dependent variable, namely health. The interaction effect on people’s life-satisfaction would pertain to the influence of one independent variable on the relationship between the other independent variable and the dependent variable (people’s life-satisfaction). The interaction effect on health would pertain to the influence of one independent variable on the relationship between the other independent variable and the dependent variable (health). For example, there may be a result that "wealthy" people with "extrovert' personality may have a greater life satisfaction, thus, providing support to the fact that the two independent variables, that is, people’s income and personality do interact with each other to produce an interaction effect on people’s life-satisfaction.