Abstract It is not easy to motivate and engage others in a way that is welcomed, effective, and relationship‐enriching. In a hierarchical relationship, supervisors' motivating styles and supervisees' agentic engagement–disengagement are often in conflict, rather than in synch. Still, reciprocal causation appears to be a naturally occurring process within these relationships, as supervisors' motivating styles longitudinally transform supervisees' engagement–disengagement, just as supervisees' engagement–disengagement transforms and summons the supervisors' motivating styles. Recognizing this, the article highlights an intervention‐based program of research designed to help infuse greater autonomy support and greater agentic engagement into the supervisor–supervisee relationship. When an experimentally based intervention helps supervisors learn how to become more autonomy supportive, interaction partners become more in synch, and this mutually supportive relationship dynamic yields numerous benefits for the supervisor, the supervisee, and the relationship. Future interventions are needed to understand what happens when supervisees learn how to become more agentically engaged. The conclusion is that relationships need and benefit from infusions of both the giving and the summoning of autonomy support.