Hi, I am confused right now. I am a newbie for SPSS. The sig. level in independent t-test is different from in two-way ANOVA. Why is that?

My dependent variable is a Likert scale type (1 to 5). For independent t-test, I used it to compare men and women. For two-way anova, i used it to see how gender and age (categorical) interacts. I put both age and gender as fixed factor. The F, sig. level for gender (in two-way ANOVA) is not the same as sig. level in independent t-test: not significant in 2way, significant in t-test.

Anyone can explain this?