Friends who talking among each other will subconsciously mirror one another, mimicking body language and enthusiasm, and showing they are both at ease. This mirroring technique is an imitative behavior that starts in adolescence and goes into adulthood, and it could also be used to influence others. If your goal is to gain the upperhand in a negotiation, this technique may be helpful.

Chris Voss, a former FBI negotiator and current CEO of the Black Swan Group, is an expert on mirroring. He believes a person's tone of voice immediately influences another person's mood and how their brain functions. According to Voss, our brains work up to 31 percent more effectively when we're in a good mood. For example, if a person sees us smile at them or detects that we are smiling by listening to the sound of our voice, we are able to "reach" into their brain, and flip the positive switch on, putting them in a better mood.

This effect is due to the mirror neurons in our brain, over which we have no control. If we intentionally put someone in a good mood, their brain will work more effectively, and that already begins to increase the likelihood of them collaborating with us.

Our tone of voice can influence how easily we can negotiate with someone. A downward inflexion is often used to say "this is the way it is; there's no other way." For example, if there is a term in a contract that there's "no movement," and we want the person to know it, and feel it without having to say those words, Voss suggests not to yell.

“I've said things like, ‘We don't do work for hire,’ just like that. It lets the other side know there's no flexibility whatsoever," he said in the video.

In order to get the person into a collaborative state of mind, we must inflect up with our voice. Using an upward inflection will encourage the person when we're questioning them. This will make them feel less attacked because when people are questioned, they feel a bit defensive.

So, if we have to question someone, if we want them to think about a different option, then we're going to have to be as encouraging as possible while still being assertive. Negotiation is an art form that can easily be learned using Voss's three tips.