Taylor, J. B. (2006). My stroke of insight: A brain scientist's personal journey. Viking.
Jill Bolte Taylor, a neuroscientist, discusses the concept of emotions lasting no longer than 90 seconds in her book My Stroke of Insight (2006). She explains that when we feel an emotion, the initial physical response in the body—such as the release of chemicals and hormones—lasts about 90 seconds. After that, the feeling starts to dissipate, unless we continue to think about the emotion or attach additional thoughts to it. This concept is often used to illustrate how emotions can be temporary experiences that we can let go of if we don't ruminate on them.
Taylor emphasizes that while the physiological experience of emotion lasts only 90 seconds, our thoughts and mental patterns can keep the emotion going far longer if we keep re-triggering it with our attention.