Actually, doing science is moral, and so is farming. Both are helping you to live a better life, which is the essence of morality.

So I agree with you that the author is totally wrong, just for different reasons.

Plenty of science exists with questionable morals. E.g. military science

If I had said, "Cars are used for transportation," would you say, "I know a guy whose car doesn't have a motor, but he sleeps in it"?

Or if I had said, "Tables are flat surfaces," would you say, "I saw a table in the museum of modern art that had a curving surface"?

So, yes, you are completely right, and I don't dispute what you're saying, but it does not invalidate the generalization. Analogously to the example cases I just gave.

There is probably some philosophical name for and explanation of this phenomenon, but I don't know what it is.

You're reading a meaning that isn't there. The author is not expecting scientists (or farmers) to be indecent, he is merely expecting them to be equally decent as non scientists (or non farmers). He's not surprised specifically that there is a positive correlation, he's surprised that there is a correlation at all.

You're right, I might have misinterpreted. He didn't actually write anything else that implies he found the positive correlation counterintuitive. I don't know what the author's actual meaning was, so I still can't say for sure, but you're right, there was some cognitive bias involved in my reading. My apologies to the author.

I think you've confused amoral with immoral.

What makes you think that? The author is the one claiming the result, which is that people who study science (which is amoral, not immoral) tend to be good people, is counterintuitive. If anyone, the author is the one in confusion.

If you thought he could've meant that people who aren't good could be amoral instead of being indecent, then you are most likely, although not absolutely wrong. Keep in mind amorality for a human is not well-defined, it is more often used to describe non-intelligent life or abstract entities. Society would consider an amoral person "immoral" in a casual sense of the word, because a person who is indifferent towards morality is per definition likely to commit immoral acts if there are no repercussions.

I see, I completely misinterpreted your comment. Apologies!

Actually, you were right to correct me to begin with, see the other reply.