LSAT 152 | Section 2 | Logical Reasoning: Q8

LR Question 8 Explanation

QUESTION TEXT: When researchers discovered that cuttlefish have the ability…

QUESTION TYPE: Paradox

PARADOX: It turns out cuttlefish don’t use “startle displays” to scare off predators. Instead, they use them to scare off smaller fish that don’t eat cuttlefish.

ANALYSIS: Animals’ base needs are simple: they want to eat, they don’t want to get eaten, and they want to reproduce. You absolutely can use this kind of common sense outside knowledge!

So, to prephrase this, I put the startle display in the that context. That led to three possibilities:

1. The small fish also eat the food that cuttlefish eat. (So scaring away small fish = more food for cuttlefish)
2. The small fish help cuttlefish predators eat cuttlefish. (So scaring of small fish helps the cuttlefish survive)
3. The small fish block cuttlefish reproduction somehow, or scaring away fish helps cuttlefish attract mates.

I made the guesses above based on my reasonable knowledge of natural selection. The LSAT expects you to have basic scientific knowledge of this sort and apply it. When you think about it, assuming that an animal wants to eat, reproduce and not get eaten is pretty basic. You don’t need to have taken biology to think through that. You just need to give yourself permission to imagine things from the cuttlefish’s perspective and what it might want in life. Humans have similar basic instincts! Eat, don’t get eaten, reproduce (i.e. sex). Humans tend to get sad if they’re missing something from that list, especially the first two.

And we do need some reason why the cuttlefish scare off the small fish. As it stands, we don’t have any reason to explain their behaviour. And animals don’t tend to use energy frivolously.

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1. If cuttlefish feed on small fish, why would they want to scare them away?
2. CORRECT. If this is true, then having small fish around is a big risk for cuttlefish: the small fish will attract cuttlefish’s predators, and the cuttlefish will get eaten. So the cuttlefish use a startle display to get rid of the small fish and reduce the risk.
3. This explains how the cuttlefish scare off the small fish, but it doesn’t explain why.
4. It’s not clear how this is relevant? This may show a way that cuttlefish can avoid predators: blending in. But, it doesn’t explain why they don’t also use the startle display against predators. Animals often have more than one defence mechanism.
5. This may explain why cuttlefish don’t need to use startle displays on predators. But, it doesn’t explain why cuttlefish do use startle displays on smaller fish.

Recap: The question begins with “When researchers discovered that cuttlefish have the ability”. It is a Paradox question. Learn more about LSAT Paradox questions in our guide to LSAT Logical Reasoning question types.