The skill of reciprocity is the ability to know how to give to get. In a hostage situation, you will find yourself in a situation where you must make exchanges. By giving the right thing, you can often get something larger in return. The essence of the skill of reciprocity is to force the hostage taker to give something in return, even though he dislikes you. One example strategy of reciprocity in a hostage situation is the "door in your face" effect. This effect states that, by asking for a large favor and being rejected, you increase your chances of receiving a smaller favor.
The skill of eliciting commitment is essential in hostage situations because the very fact you are talking with the other negotiator implies there is a potential commitment between you. The skill of commitment relies on understanding that once a person commits to something, he gains a strong desire to remain consistent. By knowing this fact and applying it, you can often coerce the hostage taker to agree to something that is not in his best interest.
Social proof is the skill of influencing others to perceive you in a way that influences their actions. In a hostage situation, how the other negotiator perceives you as a person will often sway how she acts in the situation. An example of using social proof in a hostage situation is to tell an analogous story to the hostage taker, explaining how you or someone you know has dealt with a situation similar to that of the hostage taker's. This in addition with mirroring the hostage taker's language manipulates her into feeling you are similar to her and can be trusted.
In a hostage situation, the hostage taker will at first dislike the negotiator. If you are skilled at convincing others to like you, you can overthrow the feelings of hostility in a hostage situation. Knowing what causes liking in other and applying this knowledge to the hostage situation can make the conversation smoother. Some techniques related to this skill are active listening, being nonthreatening and giving respect.