Innovation has a long and contradictory history. Before the XIX century, it was a forbidden word related to chaos, confusion, and disorder. From modern times on, besides the capitalist system and its alienation process, innovation started to be defined as a positive outcome, crossing many fields in social sciences. In this chapter, we argue that the inherently positive value of innovation converts it into a higher complex sign that regulates teachers’ human development in innovative schools. Departing from the cultural psychology of semiotic dynamics theoretical framework, this chapter has two main goals: demonstrate how the sign of innovation can trigger teachers’ human development and how the concept of persistent innovation can explain the genesis, context, and maintenance of the innovation process. The results showed that the innovation process relies on collective work and relational praxis. Persistent innovation can link social and individual dimensions to deepen the comprehension of human development in adulthood in professional contexts.