Three developments have implications for the future study of marine mammal behavior: 1) The number and affiliation of researchers have increased from a few individuals representing the interests of government or industry to many people conducting studies from a variety of points of view; 2) The interpretation of natural selection's operation on social behavior and life history patterns has shifted from emphasizing group to individual benefits; and 3) The passage of the Marine Mammal Protection Act has committed the United States to manage, research and protect marine mammal populations. Despite negative aspects of each development, the overall effect on marine mammal research will be positive. The combination of these changes and the interaction and collaboration of researchers with diverse orientations will spur new and varied research efforts and lead to a deeper understanding of marine mammals.