Summarize Argument: Phenomenon-Hypothesis
Researchers hypothesize that being exposed to germs during infancy reduces the chance people develop allergies. Their evidence is the fact that children in large families have fewer allergies than children in small families.
Notable Assumptions
The researchers assume that being in a large family generally exposes children to more germs than being in a small family.
A
In countries where the average number of children per family has decreased over the last century, the incidence of allergies has increased.
We need to compare between small and large families where all else is equal. We have no idea what environmental factors relating to allergies were like 100 years ago. Those factors could potentially explain the difference in allergies better than family size.
B
Children in small families generally eat more kinds of very allergenic foods than children in large families do.
This weakens the author’s argument. Exposure to germs isn’t what causes the difference in allergies between children in small and large families. Instead, diet causes that difference.
C
Some allergies are life threatening, while many diseases caused by germs produce only temporary discomfort.
We don’t care about the consequences of allergies and germs. We’re simply trying to strengthen the connection between germ exposure and developing allergies.
D
Children whose parents have allergies have an above-average likelihood of developing allergies themselves.
Irrelevant. This suggests allergies may be hereditary or environmental, given that children may grow up how their parents do. We’re trying to strengthen the connection between germ exposure and developing 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.
Children who were exposed to other children at a young age were less likely to develop allergies than children who weren’t exposed to other children until later. This strengthens the author’s causal claim about germ exposure (from other children) and developing allergies.