Engineers measured how much signal a wire could carry, and offices turned it into a metaphor for human attention.
The word "bandwidth" entered English in the 1930s as a technical term in radio engineering, describing the range of frequencies a communication channel could transmit.1 A wider bandwidth meant more information could pass through. The term was precise, measurable, and confined to electronics laboratories.
By the 1990s, as the internet entered public consciousness, bandwidth became a common way to describe data transfer capacity. A "high bandwidth" connection could load web pages faster. The word still referred to something physical, flowing through cables and routers.
The metaphorical leap happened in corporate offices around the same time. Workers began saying they "didn't have the bandwidth" to take on additional projects, borrowing an engineering term to describe a human limitation.2 The phrase spread through management vocabulary until it became a standard euphemism for being overwhelmed.
The metaphor reveals an assumption worth noticing. To describe human attention as bandwidth is to treat the mind as a channel for throughput, a pipe that can be widened or narrowed but whose purpose is to carry a flow of tasks.
Cognitive scientists have studied the limits of human attention without using the bandwidth metaphor. George Miller's 1956 paper "The Magical Number Seven, Plus or Minus Two" identified the approximate capacity of short-term memory.3 Herbert Simon coined the phrase "attention economy" in 1971, arguing that information consumes the attention of its recipients.4
The word continues to function differently in its two domains. In telecommunications, bandwidth is a measurable quantity. In office conversation, it is a socially acceptable way to decline work without admitting exhaustion.5