You’ve heard the expression, “born salesman.” The phrase resonates because most of us intuitively believe it to be true. After all, it takes an outgoing personality to engage people, the gift of sincerity to win their trust, and an instinct for both savvy negotiating and fair dealing to become a sales great, right? Yet experience shows it’s not always in the DNA. Many professional sales people can tell you stories about colleagues who started with personality traits that seemed incompatible with sales success, and ended up becoming masters of their craft. It wasn’t a case of applying the ironic George Burns quip — “The key to success is sincerity; if you can fake that you've got it made” — rather, these stellar sales pros studied winning techniques and practiced them over many months and years. Like Johnny Carson, who was remote and disengaged when the cameras were off, and famously brilliant when they were on, these sales “unnaturals” learned to project the qualities necessary to...