A question regarding correlation and regression for a seminar

Im doing a seminar in which the dependent variable is work centrality which is an interval one. the independent variable is age (ratio), gender (nominal), education (nominal), job satisfaction (interval) and interesting work (interval).

When I tested the correlations between the dependent variable and each of the independent variable, I found that most of the relations fit my assumptions and are significant.
Though, when I did a regression, almost non of the coefficients were found significant.
So I wanted to ask if that means that my assumptions were confirmed or not, and why?



TS Contributor
without any detailed knowledge of your data I would guess that job satisfaction and interesting work should be strongly correlated and possibly education as well. In this case one would expect exactly what you saw.