"Surprising" Phenomenon
Nuts are high in calories, yet people who eat nuts are less likely to be overweight than people who never eat nuts.
Objective
The correct answer will be a hypothesis that explains how people consuming a certain high-calorie food can gain less weight than those not consuming that high-calorie food. The explanation must result in nut-eaters mitigating their caloric intake with diet and/or exercise, or else result in the people who never eat nuts eating a higher-calorie diet overall.
A
The likelihood of becoming overweight depends not only on how many calories one consumes but also on how rapidly one burns those calories through physical activity.
This seems like a component of the explanation we’re looking for. However, we need to know that the nut-eaters are actually getting more physical activity.
B
Due to the fact that nuts are rich in calories, consuming a sufficiently large quantity produces a feeling of satiation.
This is missing a comparative aspect. How do we know the people who never eat nuts aren’t reaching the same feeling satiation on lower-calorie foods?
C
If people who avoid a certain kind of food are more likely to be overweight than people who consume that food regularly, then that food should not be avoided for weight loss purposes.
It doesn’t matter whether a food should or shouldn’t be avoided. We need to know why eating high-calorie nuts seems to be beneficial for preventing unhealthy weight gain.
D
On average, people who never eat nuts consume the same total calories per day as people who regularly eat nuts.
If both groups are eating the same amount of calories, then why are the nut-eaters less likely to be overweight? We need more information on how the two groups differ, rather than how they’re similar.
E
Most people who regularly eat nuts eat correspondingly less of foods whose taste, unlike that of nuts, stimulates a hunger response.
People who ate nuts were satisfied after eating. People who didn’t eat nuts ate food that made them think they were hungry, which led to overeating. This explains why eating nuts proved beneficial for preventing weight gain in the study.
Summarize Argument: Phenomenon-Hypothesis
The newspaper’s conclusion is a hypothesis about the effect of increased produce prices: they’ve resulted in an increase in gardening. To support this hypothesis, the newspaper points to a correlation: during the same year that produce prices rose, sales for two major seed companies also rose.
Notable Assumptions
Based on a mere correlation between produce prices and seed sales, the author concludes that produce prices are responsible for the increase in gardening. So, she assumes there’s not some other explanation for the increased sales. She also assumes that the relationship isn’t reversed—that is, increased seed sales aren’t somehow responsible for rising produce costs. Finally, she assumes a link between seed sales and gardening—namely, that increased sales at just the two largest seed companies is a reliable sign that people are actually gardening more.
A
Increases in produce prices are largely driven by increases in the fuel costs of bringing crops to market.
The cause of increased produce prices provides no info on whether those increased prices have, or have not, had an effect on gardening.
B
The average personal garden is much smaller than it was decades ago when inexpensive produce started to become available.
This suggests that perhaps gardening has declined compared to decades ago, but the argument is focused on whether, and why, gardening activity has changed since only last year.
C
Community gardens report that waiting lists for renting garden plots have gotten longer over the last year.
This suggests that interest in gardening has increased, but offers no insight into whether the actual planting of such gardens has increased or whether produce prices are, or are not, the underlying cause.
D
Personal gardens are usually popular in economic downturns.
Without knowing whether there has been an economic downturn, we can’t assess the effect (D) has on the argument Also, even if there has been a downturn, (D) still allows for increased produce prices to be the cause of the rising popularity of gardens.
E
A large retail seed company went out of business early last year.
This provides an alternative hypothesis for the increased seed sales at the two largest seed companies: one of their competitors went out of business. This undermines the author’s assumption that the increased seed sales were due to rising produce prices.
Summarize Argument
The author concludes that back belts don’t help prevent back injuries. This is based on the fact that in a study of Flegco employees, those who wear back belts are more likely to suffer back injuries than employees who don’t wear back belts.
Identify and Describe Flaw
The author overlooks the possibility that the people who wear back belts at Flegco start off with a higher risk of back injuries than the people who don’t wear back belts. For example, maybe the people who wear back belts are involved in manual labor, whereas the people who don’t wear back belts are office workers who don’t lift anything heavy. If this is true, then we can’t conclude that back belts don’t reduce injuries simply because the people who wear back belts have more back injuries than the people who don’t wear the belts.
A
It compares the incidence of back injury between two groups who probably do not have the same risk factors for back injury.
This points out that the people who wear back belts might be more at risk of back injury due to the nature of their job than are the people who don’t wear back belts. This is why the fact that the belt-wearers are more likely to get back injuries does not prove the belts don’t help reduce injuries.
B
It fails to address the possibility that Flegco Corporation employees are more likely to wear back belts than are employees who perform similar tasks in other corporations.
The argument concerns a comparison between Flegco employees. How Flegco employees compare to employees of other corporations is not relevant.
C
It takes for granted that if a factor is associated with an increased likelihood of a certain effect, that factor must causally contribute to that effect.
The author does not assume that back belts causally contribute to back injuries. The conclusion is just that back belts do not help prevent back injuries. In other words, the author could believe back belts simply have no causal relationship to back injuries.
D
It confuses the claim that a phenomenon does not causally contribute to a certain effect with the claim that that phenomenon causally contributes to preventing that effect.
The author concludes that back belts do not help prevent back injuries. This claim is not confused for a claim that back belts do help prevent back injuries.
E
It fails to address the possibility that even if a factor is sufficient to produce a certain effect, its presence may not be necessary in order for that effect to be produced.
(E) describes a confusion of sufficient and necessary conditions. But there is no factor presented as sufficient to guarantee a certain effect. So there can’t be a confusion of sufficient and necessary conditions.