Meanings
nounstreetlight effect (plural streetlight effects)
plural streetlight effects
- A kind of observational bias whereby people only search for something where it is easiest to look.
Origin
An allusion to an old joke in which a drunkard searches for his keys (lost elsewhere) under a streetlight because that is where the light is.
Full word history & related roots →Cite this entry
APA
streetlight effect. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/streetlight%20effect
MLA
“streetlight effect.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/streetlight%20effect. Accessed November 3, 2026.
Chicago
WatkinsX Dictionary, s.v. “streetlight effect,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/streetlight%20effect.
Source: streetlight effect on Wiktionary, CC BY-SA 4.0.