Hi all.

I am attempting to test a mediation hypothesis. There is a significant
correlation between my mediator variable and my DV. However, when I further
examined the nature of this relationship by regressing the DV onto the
mediator and including a quadratic term, my output indicates that both the
linear model and the quadratic model are significant, and that actually my
quadratic model accounts for slightly more variance than the linear model
(however, both Rs are small). What is the importance of this finding? Does
this mean it is inappropriate to test a mediation hypothesis given the
existence of a non-linear relationship between the mediator and DV? Or can I
go ahead with the mediation and just note that as a limitation??

Taylor Poling
Industrial/Organizational Psychology Program
University of Tennessee, Knoxville
408 Stokely Management Center
Knoxville, TN 37996-0545
(865) 974-1676