Impulse Purchases

The Gemara says in Shavuos (45a) that day laborers do not want to be paid at the beginning of the day. Rashi says the reason is that the workers need the money they are being paid for home living expenses, which they will purchase at night. They are afraid that if they are paid before the end of the day, they might spend it on something else. Impulse purchasing is not new.

Interestingly, the Rashash suggests a forced reading of Rashi where the laborer is concerned that he might drop or lose the money. The laborer is not worried about spending frivolously. Perhaps the Rashash assumed that at the time of the Mishna, food trucks did not regularly visit construction sites. This is because gas stations hadn’t been invented yet. Rashi in Bava Metzia does suggest the reason offered by the Rashash. (However, see Rabbeinu Chananel, who also assumes the worker is worried about spending his money, but for a different reason.)

Belief Perseverance

You’re at a dinner table. Someone confidently says, “Napoleon was six-foot-two.” You gently reply, “Actually, he was 5’6”,” and even show them a reliable source. They glance, frown, and dismissively mutter: “Fake news.”

Why?

Because once people make up their minds, convincing them otherwise is about as easy as teaching a cat to use Venmo. Psychologists call this belief perseverance—the idea that once a person accepts something as true, they’ll cling to it tighter than a squirrel clutching its last acorn before winter.

One classic 1975 Stanford study illustrates this well. Researchers gave participants fabricated data suggesting that certain people were either good or bad at predicting suicide. Later, they revealed the truth: the data was entirely made up. Everyone nodded in understanding. But when asked again, “So who do you think was good at predicting suicide?” participants still leaned on the original fake data—despite knowing it came from psychology students armed with a typewriter and too much free time.

Do we see a similar psychological dynamic in the Gemara?

Yes. The Gemara in Shavuos (45a) discusses a case where employers, amid the chaos of payday, become confused about which workers have already been paid. In cases of doubt, Chazal side with the worker, allowing him to swear and collect his wages. But the next day, when the dust has settled and no crowd of workers is demanding payment, the standard rule applies: possession of funds is stronger. The employer is presumed to be correct unless the worker provides proof.

Tosfos raises a question: if we expect the confusion to clear up once the pressure is off, why “bend” the rules and allow the worker to swear and collect? Why not just wait a day? The employer will remember more clearly and may admit he didn’t pay.

Tosfos answers insightfully: if the employer made his initial claim during the high-stress rush of payday—that he paid—he will stick to it even afterward, when clarity returns. He won’t reverse course. His mind has locked in the belief that he paid the worker, and now he’s emotionally invested. He’ll double down.

Belief perseverance plays a role in halachic reasoning. Once someone commits to a position, even under pressure, they’re far more likely to defend it than to rethink it.

I’m Not a Thief, I’m a Borrowologist

Let’s get one thing straight: these people aren’t criminals. They’d never mug you in an alley or sneak a candy bar into their coat at a gas station. But lend them a book, a space heater, or a lawn mower? Time to say goodbye.

These people walk a moral tightrope. They live by an unspoken code: “If I didn’t take it—just borrowed it—then it’s not stealing. It’s custodial extensionism.” Welcome to the world of the Intentional Non-Returner.

A 2014 University of Michigan study found that 34% of people admitted to intentionally not returning something they borrowed. One-third! That’s not petty theft—it’s a lifestyle.

Do Chazal discuss this phenomenon?

Absolutely. The Gemara in Shavuos (46b) presents a case where someone leaves his friend’s home holding an item. The homeowner shouts after him: “Thief! You stole that from me!” The guest replies, calm as can be: “What do you mean? You sold it to me, and I paid you.”

In this case, Chazal side with the guest. (There are additional factors discussed in the Gemara; see there.) The idea that a guest would blatantly steal something on his way out is too implausible. But if we tweak the scenario slightly, the halacha changes.

If the homeowner instead yells, “Remember to return it in a week!” and the guest answers, “Return it? I bought it from you!”—then we believe the homeowner that he lent the guest the item.

The Nesivos raises a powerful question: either way, the homeowner is essentially accusing the guest of theft. It is only the homeowners’ claim that changes; the guest’s claim remains the same. “I bought it, and I am never returning it.” Why do we believe the homeowner when he claims the guest borrowed the item and not when he claims he outright stole it?

The Nesivos explains that while we’re reluctant to believe a person would commit outright theft, we are willing to believe that a borrower might “accidentally-on-purpose” never return something. The guest isn’t a robber—he’s a borrowologist. In his mind, once the item is in his possession, turning a temporary loan into a permanent one doesn’t feel so wrong. It’s not malice—it’s rationalization.

Across all three cases—whether it’s buying things you don’t need, refusing to admit you’re wrong, or “borrowing” things indefinitely—one thread runs through them all: the human mind’s incredible ability to justify itself. We rationalize splurges as self-care, double down on bad facts to protect our ego, and rebrand theft as “extended borrowing.” Chazal understood these tendencies well. The Gemara deals with people in all their messy, relatable psychology. And it reminds us that while some things have changed over time, our behavior has not.