In JSTOR, when you type a word or phrase into the search box, you are searching by Key Word (just like Google), but if you take a look at your results list, then you'll notice that multiple Topics are listed for every article. 

These Topics are the real secret to searching a library database. They are how we have interconnected all of the information in any given area (and they'll always be there in a library collection although they will sometimes be called "Subjects" or "Descriptors"). 

The most fruitful way to narrow a search to laser-like focus is by searching within a topic. Click on any topic, and you'll receive a quick definition of the topic and be able to search within it in order to find a manageable results list.