Here is Dr. Jill Bolte Taylor's introduction to the 90-second rule.
When a person has a reaction to something in their environment, there’s a 90 second chemical process that happens in the body; after that, any remaining emotional response is just the person choosing to stay in that emotional loop.
Something happens in the external world and chemicals are flushed through your body which puts it on full alert. For those chemicals to totally flush out of the body it takes less than 90 seconds.
This means that for 90 seconds you can watch the process happening, you can feel it happening, and then you can watch it go away.
After that, if you continue to feel fear, anger, and so on, you need to look at the thoughts that you’re thinking that are re-stimulating the circuitry that is resulting in you having this physiological response over and over again.
