If you want to predict how someone will answer a question, your own best answer is a good guess. Even if you think the other person is less intelligent than you, they are more likely to say the correct answer than they are to say any particular wrong answer.

Similarly, if you want to predict how someone will think through a problem, and you lack detailed knowledge of how that person's mind happens to be broken, then a good guess is that they will think the same sorts of thoughts that a non-broken mind would think.