How to allow guest access to groups/forums

Hello,

We have installed BP 1.6.2, and further installed Forums for Groups. As of now, access to Groups / Forums is possible only to members. We would like to be able to provide access to non-members of the site as well, at least for reading the content of the topics in various groups / forums. Can this functionality be achieved? The site in question is http://psychotherapyandcounseling.org.

Thanks in advance.