The literature suggests that the success of innovation clusters is based on personal networks that connect members of scientific, educational, and business organizations, stimulating more formalized cross-boundary collaborations between the three sectors. But it is still unclear if such organizational collaborations actually correspond with these personal ties and which aspects of personal communication are most strongly associated with organizational collaborations. To investigate these issues, the authors applied network analysis to study an innovation cluster in Algarve, Portugal. They found that cross-boundary organizational collaborations corresponded with personal ties. Moreover, they found that collaborations appeared to correlate most strongly with emotional attachments between individuals.