A central theme in "A&P" is the concept of choices and their consequences. Every main character in the story faces a decision and must navigate the outcomes. These consequences are often not immediately apparent to them. Sammy, the cashier, makes the most noticeable and difficult choice, and he has some understanding of its implications. By quitting his job, he realizes this decision will have lasting effects on his life. His family will feel the impact, and he describes the situation as "sad." By standing up for his beliefs—protesting the manager's reprimand of the girls—he knows his life will become more challenging. If Sammy quits every time he faces an unpleasant situation, his life will become increasingly complicated. In the immediate future, quitting means he must find another job, and this impulsive choice could brand him as a troublemaker or outsider in his community.

The three girls also face the repercussions of entering the grocery store in their bathing suits. It is unlikely they were unaware of their inappropriate attire. In the early 1960s, women usually wore dresses, hats, and gloves in public. In their youthful desire to push social boundaries, the girls are reprimanded by an adult. They also leave a significant impression on two young men, Sammy and Stokesie, which might have been their unconscious intent. However, due to their decision to challenge societal norms, they feel embarrassed when scolded by an authority figure. Even Sammy's show of support cannot change the outcome; the girls quickly exit the store without defending themselves, unlike Sammy. From their timid reaction, it can be inferred that they are unlikely to take similar risks in the future. This encounter with authority will probably lead them to conform to societal expectations. Sammy, however, due to his impulsive defiance, is less likely to blindly adhere to arbitrary rules just for the sake of maintaining peace.

Lengel also makes a decision with unforeseen consequences. After "haggling with a truck full of cabbages," he enters the store and could have ignored the three girls, who were simply standing in the checkout line, and he was "about to scuttle into that door marked MANAGER." Nevertheless, he chooses to confront the girls in front of Sammy. If he considers any repercussions, he does not show it. He is merely enforcing the social norms of his time and place, expecting the girls to comply and assuming that Sammy and anyone else listening will agree with him.

Eventually, the girls cease their protests, just as Lengel expected, but Sammy makes a surprising decision to quit—a move Lengel did not foresee. To Lengel's credit, despite his strictness and sense of self-importance, he remains patient with Sammy. He refrains from yelling or immediately throwing him out of the store, instead cautioning him about the significant repercussions of his choice. However, it is Lengel's commitment to the social code—insisting that this incident be documented in Sammy's personnel file and affect him indefinitely—that leads to these consequences. In a small way, it mirrors a Greek tragedy. The characters in this drama are unable to behave differently, but it is not the gods who control their actions; rather, it is society, with its written and unwritten rules of expected behavior and penalties for straying from those norms.