求教各路大侠们一道狒狒逻辑题，有关因果倒置的疑惑

Bostondream

For a television program about astrology, investigators went into the street and found twenty volunteers born under the sign of Gemini who were willing to be interviewed on the program and to take a personality test. The test confirmed the investigators’ personal impressions that each of the volunteers was more sociable and extroverted than people are on average. This modest investigation thus supports the claim that one’s astrological birth sign influences one’s personality.
Which one of the following, if true, indicates the most serious flaw in the method used by the investigators?

(A) The personality test was not administered or scored personally by the investigators.

(B) People born under astrological signs other than Gemini have been judged by astrologers to be much less sociable than those born under Gemini.

(C) The personal impressions the investigators first formed of other people have tended to be confirmed by the investigators’ late experience of those people.

(D) There is not likely to be a greater proportion of people born under the sign of Gemini on the street than in the population as a whole.

(E) People who are not sociable and extroverted are not likely to agree to participate ininvestigation.
解释说这是因果倒置，但感觉上来说更像是无果无因，应该是加强才对啊，疑惑，求解释，谢谢

Bostondream

upupupupupupupup!!!!!!!!!!!!!!!!!!!!!!

Bostondream

为何么的人呢

sdcar2010

E is the correct answer.

Look at the criteria the survey used to select its pool.  One has to be born during a certain time AND one who is willing to be interviewed on the program and to take a personality test.  Those who agree to fulfil the latter requirement are probably more sociable and more extroverted than the average. Just by setting up that bar for its pool, the survey is sure to get the results they want!

Bostondream

many thanks!!

Bostondream

E is the correct answer.

Look at the criteria the survey used to select its pool.  One has to be born during a certain time AND one who is willing to be interviewed on the program and to take a personality test.  Those who agree to fulfil the latter requirement are probably more sociable and more extroverted than the average. Just by setting up that bar for its pool, the survey is sure to get the results they want!

-- by 会员 sdcar2010 (2011/3/15 19:07:51)

那也就是解释说因果倒置是不对的咯