This paper investigates leadership dynamics in research teams. It studies how principal investigators (PIs) and team members cultivate their relationship through the lens of leader-member exchange theory (LMX). Thirty-one in-depth interviews with both PIs and team members across 15 externally funded teams in the UK are analysed. The findings show that these relationships can be characterised along four influential dimensions: positional layer; informal layer; and the newly identified political layer and life domain. These layers show how PIs balance between formal and informal power structures, and, more broadly, how leadership dynamics go beyond the specific context in which a team is situated and members work. The notion "constructing working relationships" is proposed to stress on the need for both PIs and members to engage in a process of balancing potential tensions. Thus, the paper provides PIs with insights into the nature of leadership within a research team and recommendations regarding team design.