John Lewis Holland was an American psychologist and Professor Emeritus of Sociology at Johns Hopkins University.[2] He was the creator of the career development model, Holland Occupational Themes, commonly known as the Holland Codes. Represent your favorite player - John Holland with the best selection of the latest Jaylen Brown apparels and oufits from CavaliersPlayerOnline. You can proudly show your support with a new John Holland Cavaliers Jersey that displays his name and number on the back combined with official team colors and logo. Celebrate his success and add to your collection with official John Holland Cavaliers gear today.