mediate and moderate

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Senior Member
India-Local dialect
In social science research language, I find the term 'mediate' often used. I want clarity on this.

I want to use it like this.

Poverty mediates disease proneness and exposure to risk. ( I imply that poverty causes them.)

Is it correct? Secondly, does 'moderate' too give the same meaning?
  • Thomas Tompion

    Senior Member
    English - England
    This sent me off to read some social science language. I found a certain number of texts using mediate in this way. Here are two examples

    The first: We study 371 high schools in Florida to determine whether poverty mediates the relationship between segregation and rates of school disorder.

    This is the more common form, where poverty is seen as affecting two other variables, and hence the relationship between them. This is, I suppose, what led to the use of this verb.

    The second: For example, the mechanism by which area or individual poverty mediates the effect on injury rate is not well understood.

    Here the author just seems to prefer the sound of the word to something more usual, like influences, or affects. After all we are only concerned here with the influence of X (in one form or another) on Y.

    In the first example we were concerned with the effect of X on both Y and Z, and hence on the relationship between them.


    New Member
    English - United States
    In social science, both mediate and moderate involve relationships between three different variables. In your research methods classes, you may have learned about the independent variable (the thing scientists are manipulating, the cause) and the dependent variable (the thing scientists are measuring, the effect). A mediating or moderating variable affects the relationship between the independent and dependent variables. For the examples below, I'll call the independent variable "X," and I'll call the dependent variable "Y."

    A mediating variable is the reason why X affects or influences Y. For example, When I let go of a pen (X), it falls to the floor (Y). It appears that my letting go causes the pen to fall. However, there is a mediating variable: gravity. If gravity stopped working, X would no longer cause Y. In other words, gravity mediates the relationship between letting go of an object and that object's falling.

    A moderating variable influences the relationship between X and Y in a smaller way. Let's say that a certain surgery (X) gives a person with heart problems a better chance of survival (Y). A moderating variable isn't absolutely necessary for the surgery to work, but it makes the surgery more effective. Let's say that doctor's years of experience make it more likely that the surgery will work. We would say that the doctor's experience moderates the relationship between surgery and an improved chance of survival.

    For an in-depth scholarly explanation, read "The Moderator-Mediator Variable Distinction in Social Psychological Research: Conceptual, Strategic, and Statistical Considerations" by Baron and Kenny (1986).

    (I wouldn't normally necropost, but this thread was the #1 Google search when I was studying this today. I'd say that makes it important.)
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