I am currently in the process of analysing a combined-data set and in comparison both a female group data (group 1) set as well as a male group data set (group 2). While I seem to get significant relationships (t-value >1.96 in a 5%) between variables for the combined data, for the same relationship I keep getting non-significant values for both the female and male group - in both cases the t-value is hence lower than 1.96. So my question is simply: Is such an outcome possible and can occur? Please clarify and assist why this may happen with my data.
My common sense for some reason tells me that at least one of the two groups t-value should be greater than 1.96 and thus significant, given that the outcome for the combined data is significant. I am looking forward to receive assistance as quickly as possible, since I do not have much time left for this analysis. Thank you very much in advance!