Do people in a crowd behave like a set of isolated individuals or like a cohesive group? Studies of crowd modeling usually consider pedestrian behavior either from the point of view of an isolated individual or from that of large swarms. We introduce here a study of small crowds walking towards a common goal and propose to make the link between individual behavior and crowd dynamics. Data show that participants, even though not instructed to behave collectively, do form a cohesive group and do not merely treat one another as obstacles. We present qualitative and quantitative measurements of this collective behavior, and propose a first set of patterns characterizing such behavior. This work is part of a wider effort to test crowd models against observed data.