SD: Yeah, so it all starts with our nervous system, goosebumps, or as scientists like to call them piloerection happen when tiny muscles in your skin contract. AC: So how does our nervous system initiate goosebumps in the first place? Your autonomic nervous system still triggers goosebumps, but the reason behind why we get them when we’re afraid is a little different. AC: I love that goosebumps are essentially a way for our nervous system to say: “Notice this! So if you wrote a new Goosebumps story inspired by the science of goosebumps.