Meaning
A person or thing used as the subject of an experiment, test, or trial, especially one facing an untested procedure, product, or policy whose effects are unknown. Almost always used of people in this figurative sense, and often implies they have limited choice in the matter. Neutral register but often carries sympathy or mild indignation about unfair exposure to risk. Regional use: General English.
Origin
The animal is a South American rodent, neither a pig nor from Guinea, and even the animal's name is unexplained; World Wide Words surveys theories including confusion with the 'Guinea hog', corruption of 'Spanish coney', and transport on 'Guineamen' trading ships, finding dating problems with each, while 'pig' likely comes from its squeals. The figurative sense arose because the animals were standard laboratory models from at least the 1850s, used by Robert Koch in tuberculosis research and Louis Pasteur in rabies work, prized for being docile and for resembling humans in immune response, vitamin C requirement, and susceptibility to tuberculosis. The Oxford English Dictionary attributes the first figurative use, a person used like a guinea pig for experimentation, to George Bernard Shaw in 1913. Why this animal rather than the lab rat became the metaphor is genuinely unknown; Michael Quinion offers only a hunch that the famous Koch and Pasteur experiments made 'guinea pig' synonymous with experimentation.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- act as a guinea pig
- guinea-pigging
- human guinea pig
- used as a guinea pig
Usage Examples
- The new curriculum was rolled out in one district first, making its students unwitting guinea pigs.
- She volunteered as a guinea pig for the vaccine's early trials and was monitored for a year.
- Rather than treat customers as guinea pigs, the company tested the software internally for months.