Researchers have found that children in large families— particularly

Question

Researchers have found that children in large families— particularly the younger siblings—generally have fewer allergies than children in small families do. They hypothesize that exposure to germs during infancy makes people less likely to develop allergies.

Which one of the following, if true, most supports the researchers’ hypothesis?

(A) In countries where the average number of children per family has decreased over the last century, the incidence of allergies has increased.
(B) Children in small families generally eat more kinds of very allergenic foods than children in large families do.
(C) Some allergies are life threatening, while many diseases caused by germs produce only temporary discomfort.
(D) Children whose parents have allergies have an above-average likelihood of developing allergies themselves.
(E) Children from small families who entered day care before age one were less likely to develop allergies than children from small families who entered day care later.

KarishmaB · Accepted Answer

Hypothesis: Exposure to germs during infancy makes people less likely to develop allergies.

The hypothesis clearly talks about exposure to germs during infancy.

(A) In countries where the average number of children per family has decreased over the last century, the incidence of allergies has increased.

The statement talks about average number of children per family - whether the families have become smaller or fewer families are having kids, we don't know. We don't understand the distribution of kids hence it doesn't add much to the strength of the hypothesis. It doesn't tell us whether exposure to germs in infancy makes people less likely to develop allergies. Besides, we already know that children in large families have fewer allergies. So even if it did imply that families are getting smaller, it doesn't add much to what we already know.

(B) Children in small families generally eat more kinds of very allergenic foods than children in large families do.

This implies that eating allergenic foods could be responsible for allergies in small families. This actually gives an alternative explanation that instead of germs, allergenic food could be responsible. Hence it does not strengthen our hypothesis.

(C) Some allergies are life threatening, while many diseases caused by germs produce only temporary discomfort.

Irrelevant. No discussion on allergies vs diseases caused by germs.

(D) Children whose parents have allergies have an above-average likelihood of developing allergies themselves.

This links children's allergies to parents' allergies. It does not strengthen the link between germ exposure during infancy and allergies.

(E) Children from small families who entered day care before age one were less likely to develop allergies than children from small families who entered day care later.

This says that children who entered day care in infancy were less likely to develop allergies. Day care does mean exposure to many other kids and hence more germs. So it strengthens our connect between "exposure to germs in infancy" and "developing allergies".

Answer (E)

jantwarog · Answer

Notice that even though E seems a little bit like just a rephrase, the question asks for the exposure during infancy, and only answer E provides precise reference to infancy saying 'children who entered day care before age were less likely to develop allergies...'

fromsriant · Answer

A and E come close. Rest are out of scope
I eliminated A because its says average # of kids, that does not automatically result in large to small families. If E wasnt there, A would be OK answer. But E gives best reason

bhavik1995 · Answer

Isn't E saying the the opposite of what we require.
Instead of strengthening it is weakening the argument.
IMO A should be the answer.

okkk123 · Answer

after i read all the choic, i think E is the best. because we are talking about whether exposured to germs in infancy will lead to less allergic

Posted from my mobile device

yash312 · Answer

After reading the argument 
Alwyz read the question and what it intends us to do...

Read the conclusion In isolation
Hypothesis: Exposure to germs during infancy makes people less likely to develop allergies.

Prethink:there is no other factor that contributes to increase of allergy other tha. Exposure in infancy period

All choices just state thing which are enticing but wrong

Only E states that infancy is the reason for variation in allergies depending on exposure

Posted from my mobile device

akela · Answer

PowerScore Complete Question Explanation

Strengthen, CE. The correct answer choice is (E)

The researchers’ argument is structured as follows:

Premise: Children in large families—particularly the younger siblings—generally have fewer allergies than children in small families do.

Conclusion: Exposure to germs during infancy makes people less likely to develop allergies.

In other words, the researchers compared the incidence of allergies in large families vs. small families, and found that the younger siblings in large families have a lower risk of developing allergies than children in small families. They conclude that it is exposure to germs during infancy that makes people less likely to develop allergies. Because the conclusion seeks to explain an observation presented in the premise, the relationship between premise and conclusion is a causal one, and can be diagrammed as follows:

Lower Allergy Risk = Younger siblings in large families have a lower risk of developing allergies than children in small families

Germs While Young = Exposure to germs during infancy

..... Cause  ..... ..... ..... ..... .....  Effect

Germs While Young --> Lower Allergy Risk

Although the argument proceeds in a predictable fashion (the premise presents a phenomenon; the conclusion attempts to explain it), this is a challenging question due to the convoluted causality underlying the researchers’ hypothesis. In order to strengthen it, you first need to understand why exposure to germs during infancy is reasonable explanation for the comparatively low incidence of allergies among younger siblings in large families.

The logic is as follows: the more people we come in contact with, the more germs we are exposed to. Hence, children raised in large families are typically exposed to more germs by their siblings than children raised in small families. Likewise, younger siblings in large families are exposed to more germs during their infancy than their older siblings were (the elders grew up in a family whose size was smaller). It turns out that the younger siblings in large families—the ones with the greatest exposure to germs during infancy—also have the fewest allergies. On the basis of this correlation, the researchers concluded that there is a causal relationship between exposure to germs during infancy and the likelihood of developing allergies.

Correlations between two variables do not automatically imply that one causes the other, as they may be coincidental effects of another cause. For instance, what if younger siblings in large families tend to eat less allergenic foods than their older siblings? This would explain why they have fewer allergies. Also, what if small families were more common in industrialized countries, where environmental pollutants play a greater role in the development of allergies than in less industrialized countries?

To strengthen the argument, look for answers that either eliminate such alternate causes, or show an analogous case in which the cause occurs (exposure to germs), and the effect also occurs (lower allergy risk). You can also support the cause and effect relationship by showing that when the cause does not occur, the effect does not occur.

Answer choice (A): This answer choice may seem attractive, because it provides further evidence of the negative association between family size and the incidence of developing allergies. However, we have no proof that the increased incidence of allergies in countries where the average number of children per family has decreased affected the younger siblings in those families. If it did not, the increased incidence of allergies may have been caused by something other than the decreased exposure to germs.

Furthermore, we need to take into account the incidence of allergies in countries where the average number of children per family did not decrease. If children in such countries also had an increased risk of developing allergies, then clearly something other than family size (and germ exposure) must have elevated the risk in both types of countries. Since this answer choice does not present a clear comparison, it is impossible to evaluate its effect on the conclusion of the argument.

Answer choice (B): This Opposite answer presents an alternate cause for the increased incidence of allergies. If children in small families eat more kinds of very allergenic foods than children in large families do, this would explain why the likelihood of developing allergies varies by family size.

Answer choice (C): This answer choice does not address the causal relationship between family size and the incidence of allergies. The question stem does not ask you to justify exposure of children to germs in order to prevent allergy.

Answer choice (D): This Opposite answer suggests that an alternate cause may affect the incidence of allergies: if children whose parents have allergies have an above-average likelihood of developing allergies themselves, then susceptibility to allergies would be hereditary. In that case, the chance of developing allergies would be determined at birth. This is clearly at odds with the premise that younger siblings in large families have fewer allergies than older siblings, and weakens the conclusion that an environmental factor (such as exposure to germs) makes people less likely to develop allergies.

Answer choice (E): This is the correct answer choice.  If children from small families who entered day care before age one were less likely to develop allergies than children from small families who entered day care later, this provides additional evidence to support the hypothesis that exposure to other children (and therefore germs) leads to a decreased incidence of allergies. Note that this answer choice correctly compares the incidence of allergies in children from the same family size, which helps eliminate any potential biases inherent in the original study. Because early germ exposure via day care cohorts (as opposed to older siblings) results in the same decreased incidences of allergies, this answer choice presents an analogous case in which the cause occurs, and the effect occurs.

nightblade354 · Answer

Bumping for discussion! This one is another fun LSAT that hasn't been discussed in months!

abhishekmayank · Answer

Guys,

1. It is very disrespectful to assume that "day care" means exposure to "Germs"
2. More infants around, more "Germs"

unraveled · Answer

Researchers have found that children in large families— particularly the younger siblings—generally have fewer allergies than children in small families do. They hypothesize that exposure to germs during infancy makes people less likely to develop allergies.

Which one of the following, if true, most supports the researchers’ hypothesis?

(A) In countries where the average number of children per family has decreased over the last century, the incidence of allergies has increased.
(B) Children in small families generally eat more kinds of very allergenic foods than children in large families do.
(C) Some allergies are life threatening, while many diseases caused by germs produce only temporary discomfort.
(D) Children whose parents have allergies have an above-average likelihood of developing allergies themselves.
(E) Children from small families who entered day care before age one were less likely to develop allergies than children from small families who entered day care later.

One of those questions that are likely to remain questionable because of the right answer.

E certainly looks the only choice but the reasoning given or i can make both need assumptions which certainly is not the right way to answer these questions.

arya251294 · Answer

So hypothesis actually needs 2 conditions to be met-
1.) Children belonging to large families
2.) exposure to germs during infancy

Option A tells us that the "average number of children per family has decreased in some countries" and in those countries, the incidence of allergies has increased.
What if the incidence of allergies in those countries has increased not because of "fewer children per family" but because of "no exposure to germs in infancy"?

Option E helps us to directly support the fact that children from small families who entered day care(exposed to others) before age one(infancy) were less likely to develop allergies.

VerbalBot · Answer

Automated notice from GMAT Club VerbalBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.

Researchers have found that children in large families— particularly

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Researchers have found that children in large families— particularly

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards