The idea of conditioning makes stability easy because people are taught to believe they are happy with their predestined lives. Every leader or leading party wants stability and tries to achieve it through different measures.
The misuse of psychological conditioning is a key factor in explaining how the World State is able to keep the population satisfied and submissive; the society in Brave New World does unethical procedures to condition infants to not only accept their status in society, but also to like it.
We'll take a look right away. Without soma, the World State would not be able to hold as much control over its citizens as it does; soma keeps the society moving, productivity high, and complacency top priority.
The World State uses all these sciences to create stability, identity and community. For example, Bernard Marx is seen as an outcast because he only has eyes for one girl, Lenina Crowne. The boy refusing to have sex is seen as abnormal, and he must be reconditioned in the ways of the World State to maintain stability.
The problem is, although Lenina craves a monogamous relationship with Bernard, her conditioning and friend Fanny dissuade her.