Sport psychology
The next major contribution that Griffith made was in 1925, when he opened the first sports psychology lab in North America. This lab was only able to stay open for six years. After the closure of the laboratory, Griffith was contacted in 1937 by Philip Wrigley. Wrigley was the owner of the Major League Baseball team the Chicago Cubs. He contacted Griffith to offer him a job. Griffith accepted the job. He called the project Experimental Laboratories of the Chicago National League Ball Club. While with the Cubs, Griffith studied how psychological factors influenced performance. Based on the results of his research Griffith made recommendations to Wrigley. These recommendations included psychological clinics for the players, holding fielding practice, and having achievement tests to measure the athletes’ basic skills.  However, Wrigley did not follow these recommendations but was still impressed by Griffith’s work. Wrigley offered Griffith a full-time position as a sports psychologist in 1939. Griffith refused the job to stay with his family. After this Griffith did not conduct anymore major research in the area of sports psychology. Griffith was an important part of sport psychology's history. He was an important part because not only was he the first sports psychologist but he also opened the first laboratory in America that studied the relationship between sports and psychology.