A growing amount of studies examining the research and development (R&D) investment of large and publicly traded firms have consistently reported lower R&D intensity levels in family than in non-family firms. In response to performance below aspiration levels however, large family firms tend to increase their R&D spending even more than non-family firms. This research investigates whether family start-ups behave like established family enterprises regarding their investment in R&D and their response to declining performance. Addressing this previously unexplored question is relevant, because of the heterogeneity within the group of family firms and different underlying mechanisms may motivate the investment choices of different types of family businesses. Drawing on the behavioral theory, we propose that family start-ups and start-ups performing below aspiration have distinct reference foci which influence their level of research and development (R&D) investment intensity.