Self-study
Recent studies indicate a correlation between damage to human chromosome number six and adult schizophrenia. ██ █████ ████████ ████ █████ ███ ██████ ███████ ██████ ██ ████ ██████████ ███ ███████ █████ █████████████ ███ ████ ████ ██████ ████ ██████ ██ ██████████ ██████ ███ ██ ███ ███████ █████ ██████████████ ██ █████ ██ ██ ██████ ██████████ ███████ ██████ ██ █████ ██████████ ██████ ███ ███ █████ ██████████████
Summarize Argument
The author concludes that there is no causal connection between damage to chromosome six and adult schizophrenia. He supports this by pointing out that some people with schizophrenia don't have damage to chromosome six, and some people with chromosome six damage don't develop schizophrenia.
Identify and Describe Flaw
The author cites studies that establish a correlation between chromosome six damage and schizophrenia and then concludes that the two aren’t causally connected. But just because there are some exceptions to the correlation doesn’t prove that there is no causal connection between chromosome six damage and schizophrenia at all.
For example, there is a causal relationship between smoking and lung cancer, but some smokers never get lung cancer while some non-smokers do get lung cancer.
11.
Which one of the following ████ ██████████ █████████ █ █████████ ████ ██ ███ ████████ ██████
a
The argument ignores ███ ███████████ ████ ████ ███ ███ ███ █████ ██ ██████ ██ ██████████ ██████ ███ ████ ██ ██████████████
The author overlooks the possibility that not all kinds of damage to chromosome six cause schizophrenia. If some types of damage do lead to schizophrenia, then there could still be a causal connection between the two, even if they aren't always linked.
b
The argument presumes, ███████ █████████ █████████ ████ █████████████ ██ ██████ ██████ ██ ███████████ ███████
The argument actually assumes that schizophrenia is not caused by damage to chromosome six, simply because the two are not perfectly correlated.
c
The argument makes █ ██████████████ █████ ██ ██ ████████████████ ██████ ███████████
This is the cookie-cutter flaw of using unrepresentative samples. However, we have no reason to believe that the recent studies or the author’s argument are based on unrepresentative samples of people with chromosome 6 damage or schizophrenia.
d
The argument mistakes █ █████ ███ ██ ███████
The author doesn’t mistake a cause for an effect. Instead, he assumes that there is no causal connection between chromosome six damage and schizophrenia at all.
e
The argument presumes, ███████ █████████ ████████ ████ ███████████ ███████ ██████████
This is the cookie-cutter flaw of assuming that correlation implies causation. But the author concludes that there’s no causal connection at all. Instead of (E), he assumes, without providing warrant, that an imperfect correlation implies a lack of causation.