I work in a quantitative social science where it is not common to formally state hypotheses in papers or presentations. I am applying for access to public health data, and the applications ask for explicit hypothesis statements. The applications will be reviewed by boards consisting of administrators, MDs, and researchers with PhDs in fields like public health and social work. Is the norm to state a general "scientific hypothesis," or a formal null/alternative hypothesis that will be used in statistical tests?
To be concrete, I am interested in studying the effect of X on some health outcome Y, because I have a hunch that X has a negative effect on Y. In that sense, my "scientific hypothesis" might be "X has a negative effect on Y." However, I will statistically test the null hypothesis "X has no effect on Y," against a two-sided alternative, i.e. "X has a positive effect on Y" or "X has a negative effect on Y."
Which of these hypotheses should I include in my application? If it's ambiguous, what are some relevant considerations? My feeling is that the scientific hypothesis might better reflect my motivations for the study, the null hypothesis is more precise.