why does preventDefault not work but return false does

Question

Does anyone have any idea why my preventDefault code isn't working? return false returns fine, but it is my understanding that's not really the 'proper' way?

 if ($('.signup').length == 0) {
        $('.star').on('click',function(e){
            e.preventDefault();
            var starElement = $(this);
            var resourceId = starElement.parents('li').data('id');

            updateFavoritesSpan( starElement, starElement.hasClass('starred') );

            starElement.toggleClass('starred');
            starElement.parents('li').toggleClass('fvtd');
        });
        // voting
        $('.voting').on('click .up', function(e){
            e.preventDefault();
            sendVote($(this), 1);
        });

        $('.voting').on('click', '.down', function(e){
            e.preventDefault();
            sendVote($(this), -1);
        });
    }

Answer 1

return false; does both preventDefault and stopPropagation.

preventDefault stops the "default" action on the element, stopPropagation stops the event from bubbling up to the parent elements.

My guess is that there is an event on the parent that is still getting triggered when you only do preventDefault.