there are instances when negotiators should act deferentially—they should maintain a constrictive body posture, adopt a softer tone of voice, and take other steps to ensure their negotiation partner feels respected, competent and unthreatened. It all comes down to the complexity of the deal and how the person across the table is behaving. In negotiations with many moving parts, negotiators need to find a conversational dynamic that allows them to exchange information effectively, to unravel the different areas of dispute, and to ensure that all the nuances of a potential deal are fully explored. This is best achieved when two parties attain what we call “dominance complementarity,” wherein one person in an interaction behaves relatively deferentially and the other behaves relatively dominantly. - hbr.org