We all have to negotiate in life, whether it’s asking for a bigger raise, nailing down details of a contract or even getting your kids to do their homework. But how does one become a good negotiator? Attorney and negotiating strategist Corey Kupfer shares the tips in his book, Authentic Negotiating: Clarity, Detachment, & Equilibrium — The Three Keys to True Negotiating Success & How to Achieve Them. He recently joined the Knowledge at Wharton Show, which airs on Sirius XM channel 111 . An edited transcript of the conversation follows.     Knowledge at Wharton: I get the sense from your book that there is a level of dishonesty out there in negotiations that’s maybe even more than people would think. Corey Kupfer: Well, there are two things. One I would describe as inauthenticity or manipulation. A lot of negotiating training, unfortunately, is based upon game playing.…