Reading Comprehension · Science
PrepTest 136 · Section 3 · Passage 3
Questions 13–19
Before you start
Open PrepTest 136, Section 3 in your official copy from LSAC and read the passage for Questions 13–19, using the structure guide below. The passage is not reprinted here.
Structure guide
- P1: introduces a traditional view and backs it with one quick example
- P2: shows a case that does not fit the old view, reports a researcher's claim that a newer model fits better, traces where the newer model came from, and lists two ways it differs from its parent
- P3: lays out the researcher's predictions, which offer a way to check the newer model
Step 2 · The kid passage
The Tire Swing Wars
For years, the Playground Handbook said that quarrels over the tire swing always go the same way. Two kids stand face to face and hum, and whoever hums longest gets the swing. Nobody shoves and nobody bargains, because, says the Handbook, the humming habit grew up to keep everyone out of the nurse's office. Lulu's class, for example, hums every single time, and the longer hum always wins.
At the kickball field, though, Priya noticed something else. Quarrels over the pitcher's spot look different every time: sometimes kids trade, sometimes they grab and tug. Priya says a newer idea, the Trade-Off Model, fits the field better than the Handbook, because it explains why bigger, older, or more practiced kids act differently. The Trade-Off Model was borrowed from Grandpa's Shopping Model, which explains how grownups haggle at yard sales. Both models weigh each move by how well it pays off on average against all sorts of rivals: a kid will tug hard only if the spot is worth a scolding. But they differ twice. The Shopping Model assumes careful thinking, while the Trade-Off Model says gut habits and what helps the whole class over many recesses decide. And in the Shopping Model, each person decides what counts as winning; in the Trade-Off Model, winning is counted in innings played.
Priya then made predictions for two schoolyards. In the tiny yard at Elm Street, where only a few spots exist, she expects kids to tug harder than in the huge yard across town, where nearly every spot is open.
Step 4 · The courtroom tale
The Case of the Bakery Line
Mr. Whitfield snapped his suspenders. "Your Honor, the old Bakery Code says customers always settle line disputes the same polite way: whoever arrived first gets served. But at Pickle Street Bakery, line fights change every morning. Some folks swap places, some elbow ahead." Judge Plum raised an eyebrow. "So the Code is useless?" "Not useless, just a poor fit here," said Mr. Whitfield. "A newer model, borrowed from how traders bargain, explains it better: people push only when the last cinnamon roll is worth the glares. And here is how we can test it. On busy Saturdays, when only three rolls remain, the model predicts more elbowing than on quiet Tuesdays." The judge nodded. "A theory that makes predictions? Now that I can check."