The story
Unknown, but possibly from brown-nose, and often associated with the points that Girl Guides or Girl Scouts at the Brownie level (ages six through eight) receive for doing specific tasks that when accumulated earn them badges (a sign of recognition) to wear on their Brownie Uniform. First use appears c. 1944 in the The Daily Item (Sunbury).
Etymology from Wiktionary, CC BY-SA 4.0.