The information that is displayed on the Members page (age, gender, location) is pulled from your Yahoo! Profile profile. You can edit the information that appears on the Members page (or hide your age altogether) by changing your settings.

Alternatively, you can ensure that no information displays on the Members page by using an “alias” (instead of your Yahoo! ID) as your identity in your group. To create an alias:

1. Go to the Manage My Identities page of your account.
2. Click Add an alias, enter a name you would like to be known as in your group(s), and click Save.
3. Then go to the Edit My Groups page and choose the new alias from the pull-down menu in the “Yahoo! Profile” column for all the groups where you prefer to use this alias.
4. Click the Save Changes button.

Your basic information will then remain anonymous unless you choose to associate your alias with your main Yahoo! Profile profile by making it searchable (by default it is not searchable).