I collected stress data (cortisol reactivity) on 4 timepoints. Further i have some psychological measures collected on 1 timepoint. Now i want to know if the psychological measure (one measurement time point) is related to stress reactivity. I tried to calculate correlation coeficients between psychological measure and Cortisol reactivity time 1 psychological measure and Cortisol reactivity time 2 psychological measure and Cortisol reactivity time 3 psychological measure and Cortisol reactivity time 4

Is there aother way to deal with these data to answer the question if the psychological measure has an effect on cortisol reactivity (without having 4 pearson correlations whre i only can see that there are associations at time 1 and 3 but not at time 2 and 4)? Is an repeated measure Ancova (Factor: cortisol reacitiviy timne 1 tp time 4 and the psychological measure as covariate?) an alternative? Another option i am thinking about is canonical correlation (Set 1: Cortisol reactivity Time 1, 2, 3,4) And Set 2(one variable of the psychological measure) n=22 individuals.

Thank you very much for your help. It would be great if i get some hints for analysis these data.