PrepTest 122

Incorrect. Without tying these offenders to having the worst nutrition, this answer doesn't affect the argument.

Incorrect. While this answer might strengthen an argument about whether the established relationship is good news for the ability of these institutions to implement positive changes for the youth offenders, it doesn't affect whether a relationship between nutrition and violence exists in the first place.

Incorrect. This answer is way too weak to affect the argument. It discusses a" low—nutrient "food" "sometime in the days" before committing a violent crime. A single low—nutrient food doesn't mean that they had poor nutrition—eating a healthy diet but consuming one piece of candy doesn't a bad diet make. Additionally, with the timeline so loose, there's no direct temporal connection between the crime and the food. We'd say it's also likely that the offenders would report sleeping sometime in the days before the violent crime was committed, but that's not evidence the two are linked.

Incorrect. This answer is too weak in that it talks about many" of them being nonviolent. If 5% were nonviolent, that would very well constitute "many, but 95% of them being violent certainly wouldn't align with the argument.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Experiment 1 — Violent offenders choose food low in nutrients
Experiment 2 — Violent inmates placed on a high—nutrient diet improved their behavior
Conclusion — Poor nutrition causes violence

Answer Anticipation:
Arguments based on experiments/research tend to have one of two flaws—a sampling flaw, or a correlation/causation flaw.

Is there a sampling flaw here? There's no indication that the sample was too small, and the sample was of violent youth offenders—the same group from the conclusion. It's therefore unlikely that the correct answer will strengthen this argument by fixing" a sampling flaw.

What about a correlation/causation flaw? The conclusion is causal ("is at the root of"), so there's a good chance this flaw is present. Experiments almost always establish correlations, and that's no difference here—the results show a correlation between poor nutrition and violent behavior. Therefore, we can look for an answer that falls into a common category:
(1) Eliminates an alternative cause
(2) Shows more examples of cause and effect going together
(3) Establishes a control group (no cause, no effect)

This third category is looking promising because of the way the stimulus is phrased. Note that it never states that the violent offenders were more likely to choose the food with poor nutrition than the non—violent offenders—it's possible that all the youth offenders chose that food. Additionally, there's no indication that the behavior improvement wasn't seen in other groups during the time period, as well. Let's prioritize answers that establish something about the other groups!

Answer Explanation:
This answer establishes a control group, where the cause wasn't implemented and the effect wasn't seen. This strengthens the argument, implying that it was the change in diet that lowered the violent acts and thus supporting a causal link between the two. If the violent inmates who didn't have a change made to their diets also improved their behavior, then it's likely something else was the cause of the change.

Key Takeaway:
Experiments tend to have sampling flaws or correlation/causation flaws, so always start by analyzing arguments relying on experiments for these two flaws.