One reason that phone numbers in the United States are seven digits long is that __________.

Question

Quizplus · Accepted Answer

The reason phone numbers in the United States are seven digits long is based on the concept of the "magic number seven," which suggests that the average number of items an individual can hold in their short-term memory is about seven. This concept was popularized by psychologist George A. Miller in his 1956 paper, "The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information."

One Reason That Phone Numbers in the United States Are