First-line supervisors are the link between where strategic decisions are made on high with where the work of the organization gets done. The first-line leadership role is stressful because it has a high level of responsibility (and visibility), but a relatively low level of control. Frontline supervisors are charged to “take care of it,” but generally don’t have decision-making authority to go with that command. I have seen more than a few newly appointed leaders really struggle with being in charge of former peers. One more reason for the high stress load: little or no formal training or other preparation to take the lead.
Recent behavioral science research on the challenges experienced by new managers (first line and above) all are in the arena of interpersonal skills, broadly defined.