Intimacy
In The Zoo Story, Albee introduces the audience to Jerry's unconventional ideas about what it means to be intimate with another person. For Jerry, intimacy is not just about friendship – it requires a fundamental sense of understanding and compassion between two people. This kind of intimacy does not necessarily need to be accumulated over time. He believes that it can be achieved simply by approaching a stranger like Peter and "get[ting] to know somebody, know all about him" (4). Jerry's ideas about intimacy fly in the face of established social norms, which do not often encourage this kind of mingling between strangers. His defiance of received ideas about personal space can be interpreted as a critique of the alienation imposed by modern, urban society. Especially considering that Peter represents this modern, polite society, intimacy also provides a way to understand the play's primary conflict.
Animals
Jerry frequently refers to animals in his conversation with Peter – indeed, he claims to be on his way home from the Central Park Zoo when they first meet. His focus on animals has two implications.
Firstly, Jerry sees animals as a solution to his social isolation. He understands that he has a problem 'getting along' with other people, and believes that he can resolve this by practicing interaction with animals. Ironically, the kind of companionship Jerry seeks is not the sort that animals can provide or even prepare him for. Jerry is looking for someone who can understand his iconoclastic opinions on modern society and empathize with his difficult past. These kinds of sophisticated interactions are only possible with people – but when Jerry attempts them with Peter, the men are unable to truly connect because of failures in communication.
Secondly, the frequent mention of animals also underlines a greater idea that humans have a capacity to be animalistic. Peter begins the play as a self-defined, civilized, polite, urban fellow. But through his responses to Jerry's provocations, he taps into his more aggressive tendencies and ultimately participates (however unwittingly) in a murder. By focusing on the limitations of animals, Jerry also suggests that humans have these limitations within ourselves.
Urban alienation
When The Zoo Story was written in 1958, the urban lifestyle that is familiar to modern audiences would have been a relatively new concept. The 1920s were the first decade in which more Americans lived in cities than in rural areas. As American cities continued to grow, people began to find that large cities ironically offered a weaker sense of community than small towns did. This social context helps explain Jerry's deep sense of loneliness (although it can also be attributed to his eccentric personality). This kind of individual alienation in an urban context was a popular topic for many modernist writers, including T.S. Eliot and John Dos Passos. By the 1950s, these themes had diffused into popular literature and would have been familiar to Albee's audience. Jerry's attempts to find intimacy are counteracted by the depersonalization of the urban landscape, which ties this theme directly to the play's central conflict.
Failures in communication
In so many ways, Peter and Jerry are unable to bridge their differences to achieve any real communication. This communication failure occurs on both linguistic and philosophical levels.
On the linguistic level, the men have trouble conversing because they have different understandings of words and concepts. An example of this comes early in the play, when Jerry asks Peter about his family. When Peter tells Jerry that he has two daughters, Peter assumes this communicates that he is married. However, Jerry does not make this assumption, and Peter is confused when Jerry continues to task him about his family. Because the men come from such different socioeconomic backgrounds, they do not approach issues with the same definitions, and hence is their ability to achieve any real intimacy hampered.
There is also a deeper failure to communicate on a philosophical level; their opinions on life and its meaning are so different that the difference impedes their ability to connect with each other. For example, Peter states on p. 22 that people should not get everything they want; he believes that a certain amount of deprivation is essential to the human experience. Jerry, on the other hand, has experienced real suffering and misfortune, and therefore has a different viewpoint on the topic. The insensitivity of Peter's remark diminishes the tentative connection that the men have made. Ultimately, the play's tragedy results from the inevitable fact that Jerry will never find a way to communicate with a world that considers him an outsider, and refuses to try and see the world the way he does.
Capitalism and the American Dream
The 1950s is often considered the heyday of the American Dream. After World War II, the US economy boomed, and a middle-class lifestyle was more attainable than ever before. However, many of the period's greatest authors were critical of the effect this capitalist ethic had on American culture. Many of Albee's contemporaries – such as Arthur Miller and Richard Yates – wrote scathing satires of American materialism. Albee shares their skepticism about the 'American Dream'. Through Jerry, an impoverished social outcast, Albee suggests that a middle-class existence is not as attainable as it seems - and that it may not even be desirable. Jerry is harshly critical of Peter's conventional lifestyle; he argues that family life has emasculated Peter, and that the bourgeoisie are so caught up in material success that they do not pay attention to the world around them. And yet perhaps the most scathing attack of all is how desperately Jerry seems to want to be included in this world anyway. One of his many contradictions is wanting to be embraced by a world he despises, and this is one of the many forces that lead him to such drastic action at the end of the play.
Alternative sexualities
The Zoo Story's frank discussion of homosexuality was extremely unusual for its time, and for this reason, many critics interpret the play as an allegory about the repression of taboo sexual desires. Albee himself is gay, and critics including Robert Zaller consider Jerry's loneliness – and desperate fumbling for intimacy with a male stranger – to be representative of the gay male experience in 1958. There are also erotic undertones to Peter and Jerry's interaction, even when sex is not being discussed explicitly. For example, many critics have pointed out the phallic resonance of Jerry's death, which occurs through a knife-wound in the abdomen.
Albee's portrayal of alternative sexuality is closely tied to his exploration of alienation. Because America had an extremely conservative culture where sexuality was concerned, people whose desires fell outside the mainstream were often marginalized. Although Jerry's loneliness is not entirely a product of his sexuality, it can be seen as illustrative of the challenges that people with alternative sexualities had to face at the time.
Social class
One source of the awkwardness between Peter and Jerry is the vast difference in their life stories and their social class. While Peter enjoys a high salary and a stable family life, Jerry has no job and characterizes himself as a "permanent transient." This difference is not just a matter of how much money the men have; it affects everything from their philosophical viewpoints to the way they perceive the world. Because the men's lives up to this point have been so radically different, they do not share common experiences and thus have trouble understanding each other. That social class distinctions could facilitate the tragedy of this play is a tragedy unto itself.