The affective state of the thinker is an important dimension when addressing a chosen problem. Inducing positive affect has favorable effects on the ability to problem solve. Humor is one of the most common ways that individuals produce positive affect. It is embedded in the social processes between individuals, relevant to context and audience, producing affect that reduces tension and anxiety, allowing individuals to be spontaneous and less rigid. This paper discusses the research results of an instrumental case study that charted the role that humor played in the formation of working relationships in a system of four novice group facilitators. The participants engaged in an intensive collaborative process of meaning making, i.e. understanding patterns of group development, melding theory to practice, and illuminating the impact of intervention on a group's developmental trajectory. This promoted qualitative changes in their levels of expert cognitive and metacognitive thinking skills. Humor facilitated the development of these skills in unexpected ways. Data sets included videotaped debriefing and planning sessions, individual and group interviews, and written reflection diaries, covering the entire lifespan of the team. Two primary humor processes were fostered within this system: Use of Humor-affective, which were humorous statements directed to the emotional dynamics within the team; and Use of Humor-cognitive, which were directed more to the meaning-making processes of the participants. A public safe space is necessary to interface embodied, narrative, relational knowledge and professional knowledge expressed in practice. This blending of epistemic sources is key to expert thinking. Communities of practice are not immune to issues of power, and can be places where hegemony precipitates alienation. This inquiry suggests that humor served to diffuse power constructions, and facilitated the evolution of ease within the social relationships, fostering challenge and risk-taking. An ethic of care sculpted humor into a positive system characteristic.