The learning chair in Half Brother symbolizes the ethical challenges surrounding animal experimentation. Initially, others treat Zan with some respect in Richard's experiment. However, introducing the learning chair significantly changes Zan's treatment.

This chair is a physical representation of control, as it is screwed into the floor and equipped with padded straps. Despite Richard's guidelines for its use, it ultimately imposes the researchers' will onto Zan. This imposition raises ethical questions about subjecting animals to such coercive methods, and it strips Zan of any small amount of agency.

Richard insists on videotaping Zan's progress for more documented data for the experiment, leading to the chair's introduction. This decision disregards Zan's natural learning process and forces him into a more structured environment.

Zan's resistance to the chair is evident, as he signs less and throws tantrums. Despite his evident unhappiness, the chair remains until Zan's aggressive behavior severely injures a research assistant. This prompts Richard to remove the chair, revealing that the experiment prioritizes human interests over Zan's well-being.

The learning chair symbolizes the ethical dilemmas of animal experimentation, particularly the balance between scientific progress and the humane treatment of research subjects. Its presence underscores the disregard for Zan's autonomy and the exploitation of animals for human gain.