Map interests for both sides before generating solutions

Write down both parties’ known and inferred interests before proposing anything — the map reveals trades that no single position could.

Why it works

Visualizing interests across both sides simultaneously counters the fixed-pie assumption: when you can see that your counterpart cares intensely about X and you care primarily about Y, a trade that gives each the priority issue becomes obvious. Without the map, both sides default to positional splitting because no one can see the structure of what actually matters.

How to do it

1. Before negotiating, list your own interests by priority: what do you need most? What would you accept trading away?
2. List your best estimate of the counterpart’s interests — what you know, infer, and need to discover.
3. Note where priorities differ: these are the trade-able issues. Where they align, look for joint gain.
4. Use the map to generate at least three solution options before evaluating any.

Evidence

Research on perspective-taking and fixed-pie bias shows that accurate understanding of counterpart interests significantly reduces zero-sum assumptions and increases integrative outcomes. (rct)

Interest maps based on inference are only as good as the inference. Confirming interest estimates through direct conversation is more reliable than assuming you have correctly inferred what matters most.

Sources

• Thompson & Hastie (1990), "Social perception in negotiation", Organizational Behavior and Human Decision Processes

Common mistake

Only mapping your own interests before the negotiation and treating the counterpart’s interests as something to discover reactively — entering without a hypothesis about what they need leaves you with no framework for creative solution generation.