A Simple Meta-Analysis query

Hi All,

I am working on my first meta-analysis project and this may sound silly, but I am having difficulty deciding which studies to include.

I thought I had read in Hunter and Schmidt that you should only use studies that have looked at exactly the question you are looking at. However, I am looking at ethincity and performance on cognitive ability tests, and there are a lot of studies that include data on this (e.g. mean, st.dev's) in their descriptives. So am I right in thinking that it is possible to work out, for example, ethnic group differences in performance on these tests just by this information (groups sizes, means and st.dev's)?

If so, I can include other studies that don't specially look at what I am interested in, but supply the information that can be included in the meta-analysis?

I hope that makes sense. Sorry if it sounds very basic.

Thank you for reading this.