Negotiation is a form of communication. Every communication has a broad purpose: to inform, to persuade, to entertain, to provoke, to bond with the listener, and so on. Most forms (including cooperative negotiation) share a major subordinate goal of clear expression. Competitive negotiation is different.
Competitive negotiators act under conditions of uncertainty, which they strive to preserve. Generally, they share neither accurate estimations of value nor the true goals for their negotiation.  Instead, they use others’ ignorance to their advantage, seeking to claim most of the available resource. In contrast, cooperative negotiators try to increase resources by sharing information freely.
A negotiation participant’s behavior is bounded by the lowest acceptable result (their "walk-away”) and their highest desired price, (or "aspiration”). An acceptable solution lies somewhere in between, in the “zone of possible agreement” or (ZOPA),  like this:
Competitive bargaining is selfish. It asks: "How much must I give to get what I want? and "How much can I get for what I have? Competitive negotiators are miserly with information, because knowledge of their interests – the needs, fears, goals and limitations that motivate them in negotiation – could allow their bargaining opponents to make offers near the lower edge of the ZOPA, and thus to achieve settlement cheaply. 
Support for the idea that knowledge about opponents’ interests confers a negotiating advantage comes from the work of Professor Adam Galinsky. Galinsky found that those high in perspective-taking ability -– skill in determining others’ thinking—were the most successful negotiators. Forgas, et al.  equate perspective taking with understanding others’ negotiating interests. But if knowing others’ interests is so beneficial, how can a negotiator determine them?
Galinsky implies that perspective-taking ability is innate – one either has it or does not. But while it may be true that we begin life with a basic stock of this ability, we can improve it with practice.
A proven way is through role-play – interacting with another concerning a shared scenario, followed by discussion about perceived and actual interests. Training videos showing mock negotiations might be used as basic scenarios. The success of video simulation techniques in helping autistic children develop perspective-taking skills show the promise of this approach. 
Another useful role-playing technique, which has been called ‘perspective taking on steroids,’ is the use of a devil’s advocate.  This method requires a designated team-member to raise doubts, challenge the status quo, and criticize every proposal. It is the advocate’s job to highlight potential flaws in strategy and question underlying assumptions. This active questioning and challenging is ideal for unearthing unspoken interests on all sides.
While some negotiators use role-playing to increase perspective-taking capability, everyone has the ability and uses it daily. Game theorists tell us that when interacting with others, people use simulation heuristics. That is, they predict what their counterpart will do in order to make choices. They often use what is called a “Stackleburg heuristic:” assume an opponent will do what is best for themselves, and respond accordingly. 
Sometimes, we predict motivation by wrongly assuming our counterpart thinks as we do. This common assumption, called the 'projection bias,' or 'false consensus bias,’  is misleading. Yes, logic may yield a similar result given the same information, no matter who is thinking. But if we thought exactly like our counterpart, there would be no need to negotiate.  So logic must be tempered by known or suspected differences between ourselves and others.
Both the Stackleberg heuristic and the projection bias are examples of perspective-taking. But the skill is a difficult one, and openness to conflicting interpretations will minimize costly mistakes.
Negotiators’ individual issues
Negotiations are individual. Many settlements turn on factors that are not obviously ‘part of the deal’ – negotiators’ image with their constituencies, their personal relationships, their emotions, cultures and past experiences – any of which can drive negotiating behavior, and become an interest. Since an understanding of interests points the way to resolution, a smart negotiator gathers as much information as possible about the conflict and its participants before sitting at the bargaining table.
Discovering interests begins with talking to one’s counterpart, trying to form a bond and draw out real goals by asking not just what but why: “What will you do with the money?” “I may just be able to get you that, but my client is going to want an explanation. Why do you want it?” “Why not” is equally powerful: “I just don’t see what’s missing here. It’s a good offer. Why not take it?” Make your information-gathering appear necessary to the deal. “I need to explain to my client – they are getting frustrated and may walk away from the table…”
Since emotions affect bargaining behavior,  “how do you feel” about negotiating points or participants can be illuminating questions, even where rational explanations haven’t formed. Negative feelings may signal that a deal point needs to change.
If you have a very competitive adversary, they may be too suspicious to honestly share interests with you. This is normal. To overcome it, spend time building trust. Or have a neutral – like a mutual friend or mediator – gather the data. The usual cognitive biases often won’t apply. 
Routine party demands for money don’t disclose interests. First, demands are almost always inflated. Second, monetary demands are a proxy -- a means to achieve interests, not interests themselves.
Even without direct discussion of interests, watching and listening to the other party is useful. People talk about what is important to them. What do they focus on? What ideals do they subscribe to? What subjects trigger which emotions? Knowing about the other party or parties will make it easier to discover their real interests.
Learn as much as time permits about your counterpart. Start early. Gather the details of their life – ask others what seems to worry or drive them. What charities do they patronize? What specific problems do they have? What do others in that line of business worry over? How could your offer or demand affect them, personally or professionally? How can you help with their goals? Use this knowledge to build an offer that meets the interests driving their presence at the negotiation. Make it easy to say yes.
Second tier issues
The Cuban Missile Crisis provides a stark example of the importance of understanding negotiators’ individual issues. In the last half of October 1962, the U.S. and the Soviet Union came to the brink of nuclear war over the removal of missiles from Cuba. The leader of each side served an ideology and a constituency that made ‘winning’ imperative regardless of the consequences.
Premiere Khrushchev could not “lose face” before the Politburo, the Soviet Union’s ruling body. American Ambassador Averill Harriman reportedly said of Khrushchev, "If we deny him an out, then we will escalate this business into a nuclear war."  Likewise, domestic politics dictated that the U.S. could show no weakness in this context. President Kennedy remarked that if he gave in, he would be impeached. 
Eventually, President Kennedy secretly agreed to withdraw American missiles from Turkey and publicly lifted the U.S. naval blockade, pledging not to invade Cuba. In exchange, the Soviets publicly withdrew their missiles, aircraft and troops from Cuba. Each side could project toughness and save face, claiming a ‘win’, and the crisis was over.’ 
This historical episode emphasizes the importance of each negotiator’s work with factors “behind the bargaining table,” including internal conflicts in one’s negotiating team – what Robert Putnam of Harvard calls “tier II” issues.  First discussed in the context of international diplomacy, tier I is the deal-making at the table, and tier II is the negotiation away from it – mostly with one’s own side.
Tier II issues exist in negotiations where a ‘side’ consists of more than one individual and the deal needs to be ‘sold’ to a constituency. The members of the constituency may feel too much was surrendered, or not enough gained in return. They may also feel shame and anger at terms they have no power to resist.
Helping a negotiating counterpart resolve such issues (often by changing the way the deal is presented rather than its basic terms) increases the likelihood of a successful conclusion to the bargaining.  Allow face-saving and perceptions of “victory” whenever possible.
Resolving tier II issues requires some level of cooperation and discussion of internal problems, which runs counter to a competitive negotiator’s desire to withhold information. But without that discussion, many deals will not be made.
That is, cooperation is necessary to even the most competitive deal. Conversely, even where the parties work cooperatively and share information, there will be a distributive phase – a time when the value available will be apportioned between the parties in some way.  All-or-nothing deals rarely get made, because there is usually a better alternative than complete surrender.
Interests are what bring parties to the bargaining table. Meeting them is what makes a negotiation successful. Cooperative negotiators share their interests, hoping to increase overall gain. But they risk settling near their lowest acceptable offer. To avoid this fate, competitive negotiators conceal their true interests, making in harder to achieve their aims.
But no matter which orientation a negotiator begins with, they will need to balance cooperation and competition to come to an agreement, often helping the other party with internal negotiations.
The most successful bargainers are those who understand what is driving another to negotiate. The skills we use in relating to others – asking questions, predicting behavior, reading emotions, attentive listening, learning about their daily problems and their ideals – are the same skills that will help us understand our counterparts’ real interests. Knowing this should give us confidence than we can succeed in any negotiation.
By Scott Van Soye
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 Figure 1 is taken from http://makingthedealwork.com/, last visited February 13, 2014
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 See endnote v. supra.