Peterson began playing golf at an early age, a result of time he spent on them with his father. By age 14, he could beat his father at the game. For a time, he had dreams of becoming a professional Golfer like Phil Mickelson, his teammate at the University of San Diego High School. By the end of high school, he was one of the top junior golfers in San Diego. In 1990, Peterson enrolled at Arizona State University (where Mickelson had also enrolled) on a partial golf scholarship. Mickelson would go on to become a highly successful PGA Golfer, with Lee Peterson later testifying that his son was discouraged by the considerable competition that Mickelson presented at Arizona State. Randall Mell of the Fort Lauderdale, Florida Sun-Sentinel reported that Chip Couch, the father of Arizona State Golfer Chris Couch, had told Mell that he got Peterson kicked off the golf team after giving Chris a hangover after a night of partying. As Chris was the No. 1 junior in the country, Chip did not want Peterson to threaten his son's Future, and complained to the golf coach, who kicked Peterson off the team. Peterson transferred to Cuesta College in San Luis Obispo, California, and later, California Polytechnic State University. He initially planned to major in international Business, but changed his major to agricultural Business. Professors who taught Peterson describe him as a model student. His agribusiness professor Jim Ahern commented, "I wouldn't mind having a class full of Scott Petersons."