Half Brother

In this section, Zan and Ben’s deep bond, likely stemming from similar circumstances, takes center stage as Ben advocates fiercely for Zan and eventually says goodbye. The novel humanizes Zan by highlighting the parallels between the chimpanzee and Ben, including their stifling father figure, their unfamiliar surroundings, and the ways they are used by others. This section particularly emphasizes the mirroring of Zan and Ben's experiences from the perspectives of two different species, highlighting the themes of Communication and Understanding, The Challenges of Growing Up, and The Ethics of Animal Experimentation.

The mirroring starts at the novel's beginning when Ben and Zan leave their homes and travel for Richard's project, serving almost as afterthoughts to Richard’s priority—the project itself. Another critical similarity revealed in this section is the fact that their mothers wanted them, but they were undesirable to other authority figures. Zan was unwanted by the Air Force program he was born into, and Richard did not want Ben, an insult Sarah hurls at Richard during a heated argument, accusing him of “not even wanting [his] own child” (243). Worse, Richard does not see what is wrong with his actions, praising himself for having "stuck it out" with Sarah rather than leaving, further highlighting his emotional disconnect from his family, as well as his disconnect from the ethics of his overall behavior, including the experiment (243). Both Ben and Zan struggle under the control of selfish people who are not concerned with their welfare. For Zan, this leads to physical and emotional abandonment. For Ben, it is only emotional, but this is because he is human and protected by his mother. These interactions highlight Richard’s incompetence as a science experiment leader and his lack of Communication and Understanding; while many human fathers may be distant without being cruel, Richard is cruel to Zan because he views him as an object. In this sense, Ben is the opposite of his father, sharing a genuine connection and love for Zan, as well as an instinctual understanding of The Ethics of Animal Experimentation. While his parents criticize him for his poor grades, Ben exhibits the high emotional intelligence and empathy that is needed to successfully attempt a project as complex as chimpanzee language and cohabitation.

Zan and Ben’s mirroring of each other continues in their relationships with others, highlighting The Challenges of Growing Up. The interaction between Zan and Sheba, the older chimpanzee, starts well. However, Sheba is more interested in Zan's things and throws Zan across his cage. Meanwhile, Ben's relationships are more romantic, but they go no better than Zan’s. Ben's interest in Jennifer starts well but ends with him getting hurt, like Zan and Sheba. David tells Ben that Jennifer used him to make another boy, Hugh, jealous, which speaks to an objectification that is not unlike Richard’s general treatment of Zan. Moreover, like Zan and Sheba, Jennifer only gets along with Ben because she wants something. Once she has it, she hurts Ben without issue. Zan's second interaction with another chimpanzee, Rachel, goes much better, giving hope that Ben's next romantic encounter will work out better as the two continue to mirror each other.

Richard's disinterest in Ben and Zan offers another similarity, as the best way for them to gain Richard's attention is by doing something wrong. For Zan, these interactions range from throwing things to full temper tantrums. For Ben, poor grades and struggles with his temper gain Richard's attention. Richard barely notices when Ben's grades improve from Cs and Ds to mostly Bs and Cs, but he becomes furious and controlling when Ben's grades fall. These interactions continue to highlight Richard’s lack of Communication and Understanding, highlighting his desperate desire to control everything around him. In life and in his experiment, Richard’s lack of flexibility and failure to comprehend that he cannot control others ultimately leads to the unhappiness of others, as well as himself.

Zan knows over 60 signs, but it is not enough for Richard, who claims this is not proof of language. When Zan creatively calls the refrigerator a "food box," even that does not garner Richard's attention, though both Ben and Peter notice that Zan is learning. Ben even uses a school project to highlight the lack of vocabulary Zan has been given, literally giving himself the same tools as Zan to understand his limited agency, but Richard holds firm. This heartfelt plea demonstrates Ben’s resourcefulness and empathy while juxtaposing Richard’s lack of compassion and creativity. Ultimately, neither Ben nor Zan can satisfy Richard, leading to harsh consequences for them both.

Both Zan and Ben also tend to attack others when they feel unheard, highlighting the result of limited Communication and Understanding. The novel takes a turning point when Zan attacks a new research assistant, Joyce, who does not respond to his increasingly frustrated signing. To the researchers, this is an unprovoked attack indicating Zan's wildness. However, it captures Zan’s overwhelming frustration at his unmet needs: He desperately tries to sign and is ignored, so he acts out. A similar incident occurs when Richard tells Ben that they will get rid of Zan. Ben repeatedly explains his feelings with increasing frustration, as his feelings go unacknowledged in any meaningful way. When Richard refuses to consider Ben's perspective, Ben gets so angry he attacks his father. This attack also demonstrates The Ethics of Animal Experimentation because, on an ethical level, leaving Ben and Zan to grow up together with no fixed plan or boundaries means that they will grow more like each other, and Ben’s attack of his father mimics Zan’s behavior. While Zan’s behavior is natural for his species, it is not natural for Ben to attack his father. This incident demonstrates the blurring of lines in animal ethics, with the fault falling on Richard and even Sarah for entering the experiment with no comprehension of how it would end or the effects it would have on their son or Zan.

These interactions highlight parallels between chimpanzees and humans, furthering the theme of The Ethics of Animal Experimentation. While Zan is clearly a wild animal, his complex relationships and ways of interacting are not so different from the humans around him, and he comes to depend on Ben for emotional support. This mirroring deepens the interiority of both characters and underscores the ethical complexities in treating Zan as a subject rather than as a sentient being with emotions and needs. This bond challenges common perceptions about the treatment of animals as being so different from humans, as well as exploring the importance of Communication and Understanding, suggesting that being heard and understood is a universal desire transcending species.