LSAT Explanation PT 39, S4, Q13: Nearly every criminal trial includes eyewitness

LSAT Question Stem

Each of the following, if true, supports the cognitive psychologists' hypothesis EXCEPT: 

Logical Reasoning Question Type

This is a Strengthen question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage presents a hypothesis by cognitive psychologists, which states that misidentification by eyewitnesses is a common reason for mistaken convictions in criminal trials. This hypothesis can be broken down into two parts: (1) misidentification by eyewitnesses (premise) and (2) mistaken convictions (conclusion).

To simplify this concept, let's use a non-legal example. Imagine a teacher trying to identify the student who ate the last cookie from the jar. The teacher relies on the testimony of other students in the class (eyewitnesses). If these students often misidentify the cookie-eater, then there is a higher chance that the teacher will mistakenly blame the wrong student.

Now, let's create an "Evaluate" question for this argument: "Are there any other factors that could lead to mistaken convictions besides eyewitness misidentification?"

The question type for this LSAT problem is Strengthen-Except, which means we need to find the one answer choice that does not support the cognitive psychologists' hypothesis.

a) Eyewitnesses' reports are the most common reason for conviction.

This answer choice supports the hypothesis because it highlights the frequency of eyewitness reports leading to convictions. If eyewitness reports often lead to convictions, then misidentifications by eyewitnesses could also lead to mistaken convictions. Therefore, this answer choice strengthens the hypothesis.

b) In most crimes, eyewitnesses have seen the perpetrator only briefly, and people are generally poor at remembering the faces of people they have seen only briefly.

This answer choice also supports the hypothesis by providing a reason for misidentification: people are generally poor at remembering faces they've seen briefly. If this is true, it strengthens the idea that misidentification by eyewitnesses can lead to mistaken convictions.

c) The shock of witnessing a crime makes it likely that a witness's memory of the perpetrator's face will be distorted.

Similar to answer choice (b), this choice provides another reason for misidentification: the shock of witnessing a crime can distort a witness's memory. This strengthens the hypothesis by showing that eyewitnesses' memories can be unreliable, leading to mistaken convictions.

d) Judges often instruct juries about those circumstances under which testimony of eyewitnesses is fallible.

This answer choice does not support the hypothesis. In fact, it might even weaken it slightly by suggesting that judges inform juries about the fallibility of eyewitness testimony. If juries are aware of this fallibility, they may be more cautious in relying on eyewitness testimony, decreasing the likelihood of mistaken convictions due to misidentification. This is the correct answer.

e) Jurors are very likely to believe eyewitnesses who appear confident, and unreliable witnesses usually appear very confident.

This answer choice supports the hypothesis by explaining that jurors are more likely to believe confident eyewitnesses, even when those witnesses are unreliable. This increases the likelihood that misidentification by eyewitnesses will lead to mistaken convictions.

In summary, the correct answer is (d) because it does not support the cognitive psychologists' hypothesis, while the other answer choices do.