Self-study
A long-term health study that followed a group of people who were age 35 in 1950 found that those whose weight increased by approximately half a kilogram or one pound per year after the age of 35 tended, on the whole, to live longer than those who maintained the weight they had at age 35. ████ ███████ █████ ██ ████████ ████ █████ ███████ ████ ████ ██████████ ██████ ████ ████ █ ████ ██ ██████ ████████ ████ ████ ██ █████ ████ ███████████
Stimulus Breakdown
The stimulus tells us about a long-term study that tracked participants' weight and health from the age of 35 onwards. This study found that overall, participants who gained one pound per year after 35 lived longer compared to participants who didn't gain any weight. In other words, this study found a correlation between weight gain and longer life expectancy. However, other studies have found what seems to be the reverse: correlations between weight gain and health problems that lower life expectancy.
Objective: Resolve the Contradiction
We can resolve this contradiction by looking for an alternative explanation for the long-term study's results. This explanation should tell us why weight gain was correlated with longer life expectancy, while still being consistent with weight gain's correlation with health problems.
As far as we know, the long-term study was not an ideal experiment, which means there could have been confounding factors that interfered with its results. For instance, maybe many participants had a pre-existing health condition that prevented them from gaining weight while also shortening their lives.
Whatever the specifics of the correct answer, it will explain the long-term study's results in a way that is consistent with the other study results discussed. We need a clear reason why the participants who gained weight were likely to have longer lifespans.
22.
Which one of the following, ██ █████ ████ █████ ██ ███████ ███ ██████████ ███████████ █████████
a
As people age, ██████ ███ ████ ██████ █████ ██ ████ ██ █ ███████ ███ ███████ ██████████ ██ █████ ████ ███████
(A) is a clever trap answer: it wants to trick us into assuming that we need a certain amount of muscle and bone tissue to be healthy, and that weight gain lets us maintain that amount. However, those are both unwarranted assumptions, and without them, (A) doesn't work.
The problem is that (A) doesn't indicate if this change has any health effects, let alone negative health effects. The stimulus also doesn't go into this at all. That's why (A) is a trap—it doesn't have enough information to actually address the contradiction.
b
Individuals who reduce █████ ███████████ ██████ ██ ██████ ██████ ███ ███████ ████ ██████ █████ ████ ██ █████ ████ █████ ███████ ██ ████████
To resolve the contradiction, we need to explain why participants who gained weight lived longer. (B) gives us the opposite: a mechanism for how people who lose weight a particular way might live longer. That doesn't help to resolve our stimulus.
c
Smokers, who tend ██ ██ ██████ ████ ███████████ ████ ██ ████ ███████ ████ █████ ████ ███████████
Now we know there's a particular group of people who are less likely to gain weight, but have shorter lifespans. That's exactly the kind of alternative explanation we're looking for. As far as we know, the study didn't exclude smokers—so the finding that weight gain correlated with longer lifespan could be explained by non-weight-gaining smokers have a shorter lifespan.
(C) isn't a perfect explanation: we don't know for sure that the study included smokers at all, let alone enough to affect the results. However, it takes us closer to explaining the confusing results, which means it helps to resolve the contradiction. That's all we need.
d
The normal deterioration ██ ███ █████ ██████ ██████ ████ ███ ███ ██ ██████ ████ ██ █ █████████ ██ ███ ██████ ██ ████████ █████████
In other words, cutting calories can keep you healthier for longer. This doesn't resolve anything, it only deepens our confusion. We need to explain why weight gain is associated with longer lifespans, not how a weight loss strategy can improve health.
e
Diets that tend ██ ████ ██ ██████ ████ █████ ███████ ███ ████ ██████ ███ ███ ████ ███████████ ██████████████ ██ █████ ███ ███████
(E) is similar to (B) and (D) in that it only makes the contradiction stronger. To explain the contradictory study results, we need to show why weight gain was associated with longer lifespan. Emphasizing a correlation between weight gain and health problems does the opposite.