What does exogenous mean?
Exogenous is a formal adjective describing anything that originates outside the organism, system, or process being considered. Its opposite is endogenous, which refers to what arises from within. The word appears most often in technical registers. Biologists use it of substances introduced into a body from outside — exogenous hormones, for instance, versus those the body produces itself. Economists and statisticians speak of exogenous shocks or exogenous variables: events and quantities determined beyond the boundaries of a model, such as a sudden oil-price spike that disrupts a national economy regardless of domestic policy. Derived forms include the adverb exogenously and the noun exogeneity. Built on Greek roots — exo- meaning 'outside' and -genous meaning 'produced' — the word literally means 'produced from outside'. For readers of scientific and financial journalism, recognising exogenous is useful shorthand for understanding whether a cause lies inside or beyond the system under discussion.
adjectiveOriginating or developing from outside an organism, system, or process; relating to external rather than internal causes. In economics and other sciences, it describes variables or shocks that arise independently from outside the model or system under study.
- Originating externally; arising from outside an organism, system, or process.
- (Biology) Of a substance or effect introduced into the body from outside, e.g. administered hormones as opposed to naturally produced ones.
- (Economics/Statistics) Of a variable determined outside a given model, unaffected by the other variables within it.
"The recession was driven largely by exogenous factors, including a sharp rise in global oil prices."
"Plant growth can be stimulated by exogenous application of hormones to the leaves."
"The central bank treated the currency crisis as an exogenous event, beyond the reach of domestic policy tools."
In economics, an 'exogenous shock' is jargon for something nobody in the system saw coming — like an oil crisis hitting your carefully built forecast.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of exogenous
Exogenous derives from Greek elements: the prefix exo- ('outside') combined with -genous, from Greek genēs ('born, produced'), itself related to the root gen- meaning 'to give birth'. The word was formed in modern scientific Latin as exogeneus before entering English usage in the nineteenth century alongside its counterpart endogenous. It shares its productive root with words such as exotic, exodus, and indigenous.
Related word forms
How exogenous is actually used
Exogenous is a formal, technical term found chiefly in scientific, medical, economic, and academic writing. It rarely appears in casual conversation. In economics, its opposite endogenous is equally common, and the pair is standard vocabulary in econometrics.
Easily confused with exogenous
Endogenous means originating from within the system, while exogenous means coming from outside it.
'Genous' is not a standalone English word; exogenous is the full adjective combining the prefix exo- (outside) with -genous (produced).