The metaphor of “scaffolding” originates from developmental psychology, and has become a central theoretical concept that plays explanatory roles in psychology, developmental biology, and evolutionary biology. In developmental psychology, the scaffolding process is typically characterized as a child’s temporary reliance on external structure in training activities, which leads to long-term transformation of the child’s capacities. In recent attempts to clarify this concept for wider usage (e.g., Caporael, Griesemer, and Wimsatt 2014a, b; Neto et al. 2023), the temporariness of dependence on scaffolds is still seen as a typical, if not defining, feature of scaffolding explanations. In this paper, we follow Bill Wimsatt’s footsteps (Wimsatt 2014a, 2019; Wimsatt and Griesemer 2007) in examining the development of skills that require complex developmental trajectories. Our cases are jazz improvisation and scientific expertise, both of which are distinctively social and improvisational. We argue that the social scaffolds required to reach the maturity of such expertise are continually required thereafter for maintenance and further development. This is because improvisational training is somewhat indistinguishable from improvisational performance, and performance in social expertise aims at interactions, communications, and rapport between interlocutors.
