Reading ComprehensionDifficulty: Easy

PT136 S3 P3 Q19 Explanation

Evolutionary Game Theory

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsPrimary PurposeScience

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Passage

Traditional theories of animal behavior assert that animal conflict within a species is highly ritualized and does not vary from contest to contest. This species-specific model assumes that repetitive use of the same visual and vocal displays and an absence of escalated fighting evolved to prevent injury. The contestant that exhibits the one another and stretching their necks skyward; the tortoise perceived as being "taller" wins.

In populations of the spider Agelenopsis aperta, however, fighting behavior varies greatly from contest to contest. In addition, fighting is not limited to displays: biting and shoving are common. Susan Riechert argues that a recently developed model, evolutionary game theory, provides a closer fit to A. aperta territorial disputes than does the what constitutes winning; in evolutionary game theory, the payoffs are defined in terms of reproductive success.

In studying populations of A. aperta in a grassland habitat and a riparian habitat, Riechert predicts that such factors as the size of the opponents, the potential rate of predation in a habitat, and the probability of winning a subsequent site if the dispute is lost will all affect the behavior of fighting than in the riparian habitat, where 90 percent of the habitat is suitable for occupation.

What this question is testing

Primary Purpose

Your task

Pin down exactly what the question asks about the passage — a detail, the author's view, the structure, or the main point — before looking at the choices.

Common trap

Answers that restate a true detail from the passage but don't answer the specific question being asked.

Winning move

Anticipate the answer in your own words from the passage, then find the choice that matches that prediction.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
19.

The primary purpose of the passage

Answer choices

  1. Correct81% picked this

    present an alternative to a traditional

    Why this is right

    This is supported in the second paragraph.

    Skill tested: Primary Purpose · how this choice captures the passage's function is the move to repeat next time.

  2. Wrong Purpose12% picked this

    describe a phenomenon and provide specific

    The purpose is to present theories that explain behavior, not to discuss a phenomenon.

  3. Wrong Purpose3% picked this

    evaluate evidence used to support an

    No evidence is questioned in this passage.

  4. Wrong Purpose3% picked this

    present data that refutes a controversial

    No data is presented in this passage.

  5. Wrong Purpose1% picked this

    suggest that a new theory may be based on

    The author does not question Susan Reichert’s theory.

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