Viewing content on the page listings

I have a page that lists subsequent pages and there are three content fields that I want displayed on the listings page (http://sig.uwaterloo.ca/university-of-waterloo-faculty). Those three fields are Title, avatar and a short bio. As admin, I am able to see all three fields, however, general visitors are not able to see the third field, the short bio. I am using a the Zen framework.

Please help!