Manual Tests Are Divisive

Other than looking good on paper, manual tests do nothing on their own. When you find a defect with a manual test, you found the defect. When you miss one, you missed it. It's very personal, especially if you found it (or missed it) in our code.

Oh, we know we're all egoless, have collective code ownership, and we're saintlike professionals. Nevertheless, we all know exactly what we were talking about here. It's possible a person might miss something because of some flaw in the test itself, but that will happen only when it doesn't matter. When the stakes are high and something is missed, it'll be because the person doing the test screwed up. Bank on it. The tester should have seen it he just didn't, because he was distracted, under pressure, or having a bad hair day. If we had automated tests, the programmers could have caught the defect before any tester ever saw the code.