LSAT 153 | Section 2 | Logical Reasoning: Q18

LR Question 18 Explanation

QUESTION TEXT: Some killer whales eat fish exclusively, but others also eat…

QUESTION TYPE: Strengthen

CONCLUSION: Young harbor seals have an inherent aversion to all killer whales, but eventually learn to ignore those that only eat fish.

REASONING: Killer whales that eat seals chatter in different dialects than those that don’t. Harbor seals can tell these dialects apart and use this to avoid the seal-eating whales.

ANALYSIS: We know that harbor seals avoid seal-eating whales. But the passage doesn’t provide any evidence that young harbor seals avoid all kinds of killer whales. Based on the evidence passage, maybe all harbor seals know which to avoid from birth. If we had evidence that harbor seals learn to discern between the two types of chatter, the biologists’ conclusion would be more supported.

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1. This answer doesn’t provide any evidence that the seals’ behaviour is not innate.
2. This answer tells us that fish can’t hear the chatter, but that won’t help us show that the seals learn to distinguish it.
3. CORRECT. This answer gives us a scenario where harbor seals are hearing unfamiliar chatter. Even though the whale doesn’t eat fish, the seals swim away. This shows that harbor seals avoid unfamiliar chatter until they can determine whether the source is a seal-eating killer whale. All chatter will be unfamiliar to a young harbor seal, so this supports the hypothesis.
4. This answer doesn’t tell us anything useful. We learn that young harbor seals don’t show aversion to any seal predator that isn’t a killer whale. But we don’t know if they show aversion to all killer whales, or just the seal-eating ones.
5. This answer might have tricked you, because it looks like the seals are learning. However, this answer depicts seals learning to be afraid, when we are looking for evidence that they start afraid and learn to be comfortable around fish-eating whales.

Recap: The question begins with “Some killer whales eat fish exclusively, but others also eat”. It is a Strengthen question. Learn more about LSAT Strengthen questions in our guide to LSAT Logical Reasoning question types.