Why don't the epsilons need human intelligence?

Epsilons, as depicted in Aldous Huxley's "Brave New World," are designed to perform menial tasks and have limited cognitive abilities, which makes human intelligence unnecessary for their roles. Their conditioning ensures they are content with their status, and they lack the capacity to question or aspire beyond their predetermined functions. This design allows for a stable society where each caste fulfills its purpose without the need for higher-level thinking or dissatisfaction. Thus, their lack of intelligence is a fundamental aspect of the societal structure, ensuring efficiency and control.