The same content on different websites is punished by Google in many cases - nevertheless the Google algorithm is intelligent and recognizes whether the elements in the header and footer remain the same or whether entire test passages can be reached twice under different URLs. The exciting question is how Google deals with blog article overview pages.
Matt Cutts gives a brief statement on this on the Google Webmaster Help YouTube channel: The safest and most convenient option is to include articles on overview pages by means of the obligatory "continue reading" link in the form of teasers. By the way: there are over 500 videos from Google on the YouTube channel. Studying the videos is highly recommended.