While working at the Salk Institute in California, Ursula Bellugi discovered that sign language was made up of specific building blocks that were assembled following strict rules, much like in spoken language. Her subsequent discoveries about the complexities of sign language led both to linguistic breakthroughs and to changes in the way deaf people felt about signing. Bellugi demonstrated that sign language is as rich and complex as any spoken language. Her work deepened our understanding of what it means to communicate as humans.