In "A&P", Updike portrays Sammy as the protagonist working as a cashier in a supermarket under the management of his parents' friend Lengel. Sammy is shown to be an observant young man who notices and remarks on the customers in the supermarket especially on this particular day when three girls walk into the supermarket in bathing suits. After wandering around, one of the girls wants to purchase a can of herring snacks. Lengel refuses to entertain them because he thinks they are not dressed decently enough, but Sammy, in an act of childish defiance and heroism, rings up the can of herring snacks and impulsively quits his job. Thus, a comparison of Sammy's psychological and social maturity before and after the pivotal moment when the girls walk into the store reveals a forced coming of age on Sammy.
Sammy's character in "A&P" before the entry of the three girls can be inferred from his condescending and superior thoughts about his customers while observing the girls. His thoughts are crucial as they represent his social and psychological immaturity when he labels and patronizes the normal customers that come to A&P. The first example is how Sammy refers to the one of the customers as a "witch about fifty with rouge on her cheekbones and no eyebrows" despite it being his mistake in ringing up her box of crackers twice and deserving her scolding. He continues to think that this female customer would be burnt in Salem if she were born in the right era. This shows that Sammy is reluctant to admit that he deserves the scolding from the woman and his irresponsibility to be distracted instead of doing a proper job as a cashier.
Sammy's immaturity is also shown when he refers to some of the other consumers as "houseslaves" instead of housewives. The usage of the term "slaves" is derogatory and scornful as though the housewives are enslaved to their families to do housework. In addition, Sammy's depiction of customers as "sheep" who are preoccupied with their shopping debases them from human beings to animals. This is shown again when Sammy describes the customers in a comic situation to be "scared like pigs in a chute" and colliding with each other in an attempt to move away from the argument between Lengel and Sammy. These examples tell us that Sammy is contemptuous of the customers and has a tendency to be flippant about other people. His curt attitude, childishness and his treatment of life as a big joke demonstrates that Sammy is still psychologically immature.
While Sammy displays immaturity at the start of "A&P," the critical instance when the girls walk into the supermarket changes him gradually. Sammy realises that he is physically attracted to the girls, specifically the one he dubs Queenie. This is shown when he is first distracted by the girls walking in followed by his detailed observations about the sensual areas of their bodies. Sammy illustrates Queenie being "more than pretty" when her swimsuit slips to show her shoulders and the slow manner that Queenie turns makes his "stomach rub the inside of [his] apron." Sammy also describes how the jar of herring snacks "went heavy in [his] hand" when Queenie took out "a folded dollar bill out of the hollow at the centre of her nubbled pink top," in other words, her cleavage, and how he finds that "so cute." However, Sammy's physical fascination with the girls also results in him rashly quitting his job in an attempt to impress Queenie and thus showing his immaturity. Nonetheless, by using the girls, Updike seems to suggest that "A&P" is meant to be a bildungsroman because Sammy's physical attraction and attention to the opposite gender is evidence of him psychologically maturing.
Sammy's maturity is developed further when he is suddenly aware of the societal issue of status. Sammy is unintentionally able to see the difference in social standing between Queenie and himself and how society's classes can clash. As mentioned earlier, Sammy has always thought dismissively of the customers but now, Queenie is makes him visualise, in detail, her living room, her parents and their guests "standing around in ice-cream coats and bow ties" while "picking up herring snacks on toothpicks off a big plate," all through her voice and words. Furthermore, Sammy also envisages both her parents and their guests "holding drinks the colour of water with olives and sprigs of mint" (probably liquor) as a contrast to Sammy's own parents serving their guests lemonade and the occasional Schiltz (a working-class beer) in novelty glasses. The comparison of drinks served highlights the difference in social class. In this situation, Sammy is unaware that he actually matures because previously, he only comments superficially about people like the 'witch' and the 'sheep' whereas now, he makes more insightful judgements about other people albeit him being wrong.
Lastly, Sammy gains maturity when he realises a modicum of truth - the fatality of his foolish move. He also sees that the moment he "begins a gesture, it's fatal not to go through with it." It is this precise moment when Sammy understands what he has done was reckless and insensible but is unable to undo it because of personal pride. This statement shows that Sammy is now able to differentiate clearly between right and wrong and hence regrets what he has done. Updike portrays Sammy as initially leaving his job in order to attract the girls but when he does so, it becomes more of an escape from the boundaries of society and Sammy's own life. Hence it can be said that the deeper purpose of Sammy quitting his job is as a rebellion against conforming to social rules and regulations because after leaving, Sammy was able to foresee that the girls would be unaware of his 'heroic' act and leave him without reward and empty handed.
The ultimate moment of Sammy's maturity is when he feels "how hard the world [is] going to be to [him] hereafter." This reveals how even though Sammy decides to quit his job because he does not want to conform to societal rules, he "[looks] back in the big windows" and realises that resistance is not a straightforward and effortless journey. Moreover, he says that while his family thinks that he leaving his job is a sad part of the story, he "[doesn't] think it's sad" because he sees that eventually, some good has come out of what he has done. By quitting, he has been forced to grow up, to stop being reliant on his parents, Lengel and his job at A&P, and to start being independent. These lines show that Sammy is now thoughtful and reflective of what he has done - characteristics of a mature adult.
In conclusion, this essay examines the measured process of Sammy growing in all aspects of a human being. Sammy's state of maturity is seen to revolve around the crucial entrance of the bikini clad girls and the events that follow and his mental transformation from an immature teenager to a mature adult frame of mind is proved by the analysis of his habits and mindset before, during and after the girls' entrance. While Sammy's growing up can be dismissed as trivial, it is also possible that Updike is making a social commentary specifically on the division of social class and the emphasis on conformity in American society during the years following up to 1932.