Possible Theories:
* Physiological Reaction: When people experience intense fear, they can experience a range of physical reactions, including muscle tension and even temporary paralysis. This physical "stiffness" might have been the inspiration for the phrase.
* Folklore: Some believe the phrase comes from old wives' tales about people being so terrified they literally turned to stone or wood. This could be linked to stories about Medusa turning people to stone with her gaze.
* Metaphorical Connection: The phrase might have evolved as a metaphor, comparing the feeling of intense fear to the feeling of being frozen or immobile.
No Definitive Source:
There is no clear, documented origin for the phrase "scared stiff." Like many common idioms, it likely developed organically over time, drawing on different cultural influences and observations.
Regardless of its origin, the phrase "scared stiff" effectively conveys a sense of overwhelming fear and the physical and emotional paralysis that can accompany it.