When I run a 2x4x5x6 (Sex*AgeGroup*HighestDegree*Ethnicity) MANOVA (with 20 dependent variables) in SPSS, it presents tests of between subjects effects for each of the IVs and their interactions after the main MANOVA stats as a kind of post hoc. I thought these tests were 2*4*5*6 factorial ANOVAs for each of the DVs examined in the MANOVA. But when I run those factorial ANOVAs separately, I get completely different results! (The F values in the MANOVA post hoc are generally higher than the F values resulting from the separate factorial ANOVAs.) Why is that? I know I shouldn't trust the main MANOVA stats (Pillai's trace, etc.) because the cell sample sizes are way too small, but I'm at a loss as to why the post hocs from the MANOVA are different from factorial ANOVAs for each of the DVs.