Planet A is a habitable world, that looks and feels much like the West on Earth. Capitalism is the dominant ideology.
Plan(et) B is a habitable world, where a form of anarchism is the dominant ideology and has been since its inception hundreds of years ago. This anarchism is centred on the idea that power corrupts and that any hierarchy that cannot be ethically justified must be dismantled. In this system, there are no private possessions or belongings; jobs are allocated according to the needs of the society; and a very small government exists only to ensure that resources and jobs are allocated fairly. The technology required to meet basic needs (medicine, food etc) exists.
Given this has existed for hundreds of years, people's behaviours and norms are different from Planet A.