system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does sexual arousal work? How do humans get aroused by looking at a picture? How does it trigger?
gpt
Humans haven't evolved out of the mating dance yet. For a hundred million years, there was tremendous pressure to breed and no accurate way to simulate the image of a ready and willing partner. If you saw a sexy specimen in a provocative position, they were definitely real and almost certainly making an invitation. Once your eyes have seen it, your brain predicts the next part and tells the rest of your body to get ready with a rush of hormones, initiating a physical response in the pants region. This specific hardware, linking the sight, scent, sound, taste, or touch of a willing partner to your genitals is some of the oldest, simplest hardware in your brain. It doesn't know what a photograph is and that you can't have sex with it.