Translation guide
The English word "intelligence" covers several distinct concepts: cognitive ability, secret information, and the organizations that gather it. Japanese uses different words for each, and the best choice depends on what you want to express.
Talking about someone's mental capacity, cleverness, or general smartness.
The standard word for intelligence as a measurable cognitive ability, often used in psychology, education, and everyday contexts.
彼は知能が高い。
He has high intelligence.
知能指数を測るテストを受けた。
I took a test to measure my intelligence quotient.
Refers to intellectual capacity with a nuance of wisdom, depth, or cultured intelligence. Often used for people, animals, or even AI.
彼女の知性には感心する。
I admire her intelligence.
イルカは高い知性を持っている。
Dolphins possess high intelligence.
A casual, everyday way to say "smartness" or "how smart someone is." Literally "goodness of head."
彼の頭の良さは誰もが認めている。
Everyone acknowledges his intelligence.
Intellectual power or mental strength, often used in contexts like games, puzzles, or academic competition.
このゲームは知力を試される。
This game tests your intelligence.
Referring to information gathered secretly, especially for military or political purposes.
The most common word for "information," but in espionage contexts it means "intelligence." Often combined with other words like 諜報 (ちょうほう) for clarity.
敵の情報を集める。
Gather intelligence on the enemy.
その情報は機密扱いだ。
That intelligence is classified.
Specifically means espionage or secret intelligence activities. Often used in compounds like 諜報活動 (espionage activities) or 諜報機関 (intelligence agency).
Referring to the organization or group responsible for gathering secret information.
Standard term for an intelligence agency or organization.
その国は強力な情報機関を持っている。
That country has a powerful intelligence agency.
知能 is the most clinical and measurable (like IQ). 知性 implies depth, wisdom, or cultured intellect. 頭の良さ is casual and often refers to quick-wittedness or academic smartness. Use 知能 for formal discussions of cognitive ability, 知性 for praising someone's intellectual depth, and 頭の良さ in everyday conversation.
知能 only means cognitive ability. If you say 知能を集める, it sounds like you're collecting IQs. Use 情報 or 諜報 for secret intelligence.
彼は諜報活動に従事していた。
He was engaged in intelligence activities.
Loanword from English, used in specific contexts like military or business intelligence. Often part of compound terms.
インテリジェンス機関がその情報を分析した。
The intelligence agency analyzed the information.
More specific term for an espionage or intelligence agency, emphasizing secret operations.
諜報機関のエージェントが逮捕された。
An agent of the intelligence agency was arrested.