You--By not randomly assigning people to these two conditions, you may be capturing just individual differences in the kind of person who, when there's a perfectly stable, safe, low bridge, says, "Huh uh. I won't want to go on that bridge.

如果两种情况下的受试者不是随机安排的，或许你所捕捉的,只是一类人中的个体差异，这类人，当看到一个更稳定，更安全，更低的桥，会说，“啊哈，我不走那座桥。

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