A chimpanzee raised by Ben's family, learning to communicate using American Sign Language, and challenging perceptions about intelligence and animal treatment.

A scientist working on a doctorate, balancing nurturing roles within her family, particularly involving her son, Ben, and husband, Richard, while advocating for Zan's welfare.

A controlling psychologist and father, focusing on status and control in both his professional experiments and family life.

A research assistant with a love for animals and a relaxed demeanor, valuing the well-being of Zan over experimental results.

A family that influences Ben's social life and perspectives, with complex dynamics and differing views on parenting and societal expectations.

A group of characters including Susan Wilkes, Ryan Cross, Shira Mavjee, and Joyce Lenardon, each with distinct approaches to research and interpersonal dynamics.

Local public school children, including Tim Borden and Mike, representing varying social backgrounds and influencing Ben's views on friendship and class differences.

A tall, thin antagonist in the primate studies program known for his harsh methods and complex ethical stance on animal research.