Current directions in mediation analysis

ABSTRACT—Mediating variables continue to play an im-portant role in psychological theory and research. A me-diating variable transmits the effect of an antecedent variable on to a dependent variable, thereby providing more detailed understanding of relations among variables. Methods to assess mediation have been an active area of research for the last two decades. This paper describes the current state of methods to investigate mediating variables. KEYWORDS—mediation, indirect effect, statistical methods Mediating variables have been ubiquitous throughout the history of psychology because they are used to explain how or why two variables are related. One of the oldest models in psychology, the Stimulus! Organism! Responsemodel, specifies mediating processes in an organism that transmit a stimulus to a response