This is not the answer. I believe it d9es use that as one metric, but what you don't realize is that when you click that box, it is giving Google consent to scan your history and analyze it for human like patterns. If your history is repeated attempts at sites trying to download this or that, or whatever a bot might be set to do, then it would block. Bur if you browsed reddit, then hopped on Amazon, and google the definition of conalingus l, then watched YouTube, the algo would know you are human.