Logical reasoning PrepTest 157 · Section 2 · Question 18

This doesn't match our anticipation. Moreover, it doesn't bring up the new idea from the conclusion — that gesturing "helps speakers quickly find the phrases they want." Instead, it just says that almost everyone gestures when speaking quickly and with little repetition. That may strengthen this argument (since it shows gesturing is associated with quick and concise speech outside of the study), but it doesn't prove that the conclusion is true. For instance, even if (A) is true, gesturing could help people speak more quickly and with less repetition because it makes people more relaxed, not because it helps them locate the phrase they want to use.

This doesn't match our anticipation. Moreover, it doesn't bring up the new idea from the conclusion — that gesturing "helps speakers quickly find the phrases they want." Instead, it just tells us about the cartoons chosen by the researchers. Regardless of how varied these cartoons were, this answer choice tell us anything about how gesturing helps people speak more quickly and less repetitively or whether it allows people to locate the phrases they want to use.

Moreover, this answer choice may weaken the argument. If the cartoons were chosen from various sources, this introduces a new variable to the study. The study results would be more persuasive if all the subjects were asked to describe the same cartoon. If the cartoons were different, it's possible that those who were allowed to gesture spoke more quickly and with less repetition because the cartoons they described were simpler or less action-packed.

This answer choice matches our anticipation! As we anticipated, it connects the argument's premise to its conclusion. We may need to translate or diagram this answer choice to see that it bridges this gap. To do so, we can recall that the word "any" is an "if" keyword. So, we can translate this claim to, "If a behavior is correlated with quicker speech and less repetition, then it helps speakers find the phrases they want quickly." That is a precise match for our anticipation, so we can select (C) confidently.

After all, if we add this premise to the argument, it becomes valid. Suppose that (C) is true. In that case, we know gesturing, which the study shows is correlated with quicker and less repetitive speech, must help people quickly find the phrases they want. So, this answer choice makes the argument valid. We can select it and advance to the following question.

This doesn't match our anticipation. It doesn't connect the author's premise to their conclusion ("If a behavior is associated with speaking more quickly and less repetitively, then the behavior helps speakers find the phrases they want to use"). Instead, it connects the author's conclusion to their premise ("If a behavior helps speakers find the phrases they want to use, then that behavior is associated with speaking more quickly and less repetitively"). The correct answer to a Strengthen with a Sufficient Premise question should resemble "Premise → Conclusion." It can't go the other way — it shouldn't resemble "Conclusion → Premise." For this reason, (D) is incorrect.

This doesn't match our anticipation. It doesn't even bring up the new idea from the conclusion — that gesturing "helps speakers quickly find the phrases they want." Instead, it just says that the subjects who gestured the most spoke the quickest and with the least repetition. This information may strengthen this argument, as it affirms that there's a positive correlation between gesturing and speaking quickly and concisely. But it doesn't prove that these people spoke quickly and concisely because gesturing helped them find the right phrases. Even if this answer choice is true, these subjects could have gestured the most and spoken the most quickly because they were the most energetic subjects, not because gesturing helped them find the phrase they wanted to use.