well i just tried to add my email address there and it has an option to refresh the email in certain amount of time the default is 15 minutes. you can lower that to lets say an hour maybe?... but it depends really how many things you have linked to the Social Hub you gonna have to go into each account inside that app and see what the refresh intervals are set to, overall this app seems pretty useless to me but that's because i don't have any social networks and get my email via the gmail application. looks like it could be a real battery hog if configured to refresh often. or
you can remove all accounts from there so this way it will not refresh and then see if you get any battery improvements. to do this go to Settings-Applications-Manage Applications-All-Social
Hub-Clear Data
you can see more information in this thread i just found:
Removing Samsung Social Hub - Android Forums