Self-study
Support A cat will not be affectionate toward people unless it is handled when it is a kitten. █████ ███ ███ ████ █████ █████ ██ ████ ██ ███ ██████ ███ ███████ ████ ██ ███ █ ███████ ████ ███ ████ ██ ████████████ ██████ ███████
Argument Breakdown
The stimulus starts with a general rule: a cat will not be affectionate toward people unless it is handled when it is a kitten. We're then told that Paula plans to give her friend a cat that was handled when it was a kitten. The author concludes that this cat will be affectionate toward people.
Analysis: Flawed Reasoning Pattern
Let's diagram the conditional rule in the stimulus. A cat will not be affectionate toward people unless it is handled when it is a kitten — so if a cat is affectionate toward people, it must have been handled when it was a kitten:
affectionate → handled as kitten
We know the cat Paula is going to give to her friend was handled as a kitten. The author concludes that therefore, this cat will be affectionate toward people:
handled as kitten → affectionate
In other words, the author flips around the necessary and sufficient conditions. From the necessary condition of the conditional rule given above (a cat is handled as a kitten), she concludes the sufficient condition (the cat is affectionate toward people). So we're looking for an argument that provides a conditional rule, and then commits the same error, by inferring the sufficient condition from the necessary condition being satisfied.
3.
The flawed reasoning in the ████████ █████ ████ ███████ █████████ ████ ██ █████ ███ ██ ███ ██████████
a
Tulip bulbs will ███ ███████ ███████ ██████ ████ ███ ███████ ███ ███ ███████ █████ ███ █████ █████ ██ ███ ████ ███ ████ ███ ███████ ███ ███ ███████ █████ █████ ████ ███ ███████ ████████
(A) tells us that tulip bulbs won't produce flowers unless they are chilled for two months. So if they produce flowers, they must have been chilled for two months:
produce flowers → chilled for two months
We're then told that these tulip bulbs have not been chilled for two months, so they won't produce flowers:
/chilled for two months → /produce flowers
But this isn't a sufficiency/necessity confusion. This is just the contrapositive of the conditional rule first provided. So this argument isn't flawed, and (A) isn't what we're looking for.
b
Beets do not ████ ████ ██████ ███ ████ ██ █████ ████ ███ █████ ████████ █████ ███████ ██ ██████ █████ ███ █████ ██ ████ ████ ███ ███████ █████ ███ ████ ██ ███ ████ ████ ███████ █████ ███████ ██ ██████
This says that beets don't grow well unless their soil contains trace amounts of boron. We can map this as:
grow well → soil contains boron
We're then told that since the beets in this plot are growing well, the soil in this plot must contain trace amounts of boron. This follows the rule given above, and doesn't commit a sufficiency/necessity confusion. So (B) isn't what we're looking for.
c
Fruit trees will ███ ███████ ████ █████ ██████ ████ ███ ██████ █████████ ████ ███ █████ █████ ██ ███ █████ ███████ ███████ █ █████ ██████ ██ █████ ██████ ████ ████ ████ ████ ██████ █████████
(C) tells us that fruit trees won't produce much fruit unless they are pruned properly. In other words, if they do produce much fruit, they must have been pruned properly:
much fruit → pruned properly
(C) then argues that since the local orchard's trees produce a large amount of fruit, they must have been pruned properly. As in (B), the conclusion of this argument follows from the conditional rule that is provided, and there is no sufficiency/necessity confusion. (C) isn't what we're looking for.
d
Cranberries will not ██████ ██████ ████ ███ █████ ██ █████ █████ ███ ███████████ ██ ████ ████ ███ ███ █████ ██ █████ █████ ███████████ ████ ███ ███████
(D) tells us that cranberries will not thrive unless they are grown in bogs. So if cranberries thrive, they must be grown in bogs:
thrive → bogs →
(D) then states that since this area's cranberries aren't grown in bogs, they won't thrive:
/bogs → /thrive
This is just the contrapositive of the rule given above. There's no sufficiency/necessity confusion here. So (D) isn't what we're looking for.
e
Grass seeds will ███ █████████ ████ ██████ ████ ███ ███████ ██████ ████ ███ ███████ ███ █████ █████ ████ ██ ████ ████ ████ ███████ ██████ ████ ███ ███████ ██ ████ ████ █████████ █████
(E) tells us that grass seeds won't germinate well unless they are pressed firmly into the ground. So if they do germinate well, they must have been pressed firmly into the ground:
germinate well → pressed firmly
Then (E) argues that because these grass seeds in this yard were pressed firmly into the ground, they will germinate well:
pressed firmly → germinate well
This conclusion relies on a sufficiency/necessity confusion, like the conclusion in the stimulus. So (E) is the answer choice we're looking for.