No English grammar book in Korea taught me that this "reinforcing" can be ",which reinforces". I've always learned that such participial phrase's subject is the subject of the sentence or the antecedent noun. How to tell these three? I think it's the context it's in. Just confirm to me that this is neither "and none reinforces" nor "such interests reinforce", but ", which(the whole previous sentence) reinforces"
ex)People anticipate regretting actions more than inactions.However, Gilovich and Medvec found that the very opposite pattern is obtained when people look back on thier lives...Many people regretted not pursuing interests such as golf or stamp collections; none regretted wasting time on such interests, reinforcing the point that, when looking back on our lives, it is our failures to act that we regret, not our actions.