LSAT 104 | Section 1 | Logical Reasoning: Q18

LR Question 18 Explanation

QUESTION TEXT: Astronauts who experience weightlessness frequently…

QUESTION TYPE: Strengthen

CONCLUSION: Motion sickness is caused when the brain gets conflicting information about whether the body is moving.

REASONING: The astronauts can see they are moving, but their inner ears tell them they are still.

ANALYSIS: We can strengthen the argument by showing a situation where people get sick when their eyes and inner ear disagree. Or we could show a situation where people don’t get sick when their eyes and inner ears do agree.

The right answer does both.

___________

1. CORRECT. If you’re on a rough boat, you feel movement. If you don’t have a window, you can’t see it. This difference makes you sick, and supports the hypothesis.
    
   When you have a window, you see movement too. So you’re body feels and sees the same thing. Since this doesn’t make you sick, it supports the hypothesis.
2. This doesn’t help. We need to know if the airline passengers can feel they are moving, and whether they can see out the window.
3. “Some” is a very vague word. This could mean that two out of one billion passengers get motion sickness in this situation. That’s not meaningful.
4. This weakens the argument. It doesn’t seem to matter whether you can see out the window and see your motion.
5. The argument never said that every astronaut will get motion sickness. But this slightly weakens the argument, by showing that the cause doesn’t produce the effect 100% of the time.

Recap: The question begins with “Astronauts who experience weightlessness frequently”. It is a Strengthen question. Learn more about LSAT Strengthen questions in our guide to LSAT Logical Reasoning question types.