So, I have this dataset with a hormonal measure as independent variable and behavioral measures as dependent variables. I am using a linear regression as my model and after a backward selection, ended up with 4 significant dependent variables. However, I forget to include in it the age and sex of individuals. So my question is, in order to include them in the model and keep them for control, can I procede to my backward elimination by ignoring these 2 variables and keeping them in there despite their p-values of 0.7-0.8? Or I should simply remove them when they become the least significant vars?
Is there also any other way to control for two variables without using them as dependent variables?
Thank you! Jessica