LSAT 131, Section 4, RC Passage 4, The Ultimatum Game

RC Passage 4 Explanation

PASSAGE TEXT: In an experiment, two strangers are given the opportunity to share $100, subject …

Paragraph Summaries

1. The Ultimatum Game lets one person propose a split of $100 and the other either accept or reject it. If the offer is rejected, neither person gets anything.
2. Most proposers offer close to an even split, and very low offers are usually rejected. This is puzzling because a purely self-interested responder should accept any positive amount.
3. One explanation is that fairness evolved because prehistoric groups depended on cooperation. But this mainly explains generous offers by proposers, not rejections by responders.
4. A better explanation is that humans evolved in small groups where reputation mattered. Rejecting unfair offers signaled that one would not tolerate exploitation and helped secure better treatment in future interactions.

Analysis

The passage revolves around this question: Why would someone reject free money?

The traditional economic assumption is simple: if I offer you $1 instead of $0, you should take it. One dollar is better than nothing. So responders rejecting low offers looks irrational.

But the author doesn’t conclude that humans are irrational. Instead, the passage argues that our behavior makes more sense once we zoom out from a single interaction and think evolutionarily.

The first theory is essentially a cooperation story. Small hunter-gatherer groups survived because members depended on one another. Fairness norms would have promoted group cohesion and prevented destructive internal competition. But notice the limitation: this can explain why proposers tend to make fair offers. If cooperation matters, you might voluntarily share more equally. It doesn’t really explain why responders hurt themselves by rejecting an unfair offer.

The second theory is a reputation story, and the author clearly prefers this one. In ancestral environments, interactions were usually repeated and public. Your response to one low offer wasn’t just about that one transaction. It was information other people could use. If you accepted tiny shares, others would learn they could exploit you. If you angrily rejected unfair treatment, people would learn to offer you more in the future.

So our emotions evolved for those repeated social settings, not for artificial anonymous experiments. The Ultimatum Game strips away reputation effects, but our brains don’t.

The anger and self-esteem that evolved to protect our long-term interests still get triggered, leading us to reject low offers, even if taking the $1 now would maximize material gain.

So behavior that looks irrational in a one-shot experiment may actually reflect emotional mechanisms that were highly adaptive over evolutionary time. That’s the author’s point.