I have two variables. Sense of belonging and anxiety. I found a Pearson's correlation that was weak but significant. The significance was probably due to sample size (n=400). Then I conducted a t-test of high and low sense of belonging and anxiety. The t-test found a significant difference between the group of 0.6, had a medium effect size. I'm having trouble now though because I don't understand how one can say there is weak/no relationship and then the t test indicates there are significant differences between the groups. Can anyone help me 'get' why this happens/what it means?
I don't think there is a contradiction I just don't understand how to interpret the results.