What evidence supports the notion that seven is the magic number for short-term memory?
The correct answer and explanation is:
The idea that seven is the “magic number” for short-term memory comes from a study by psychologist George Miller in 1956, titled The Magical Number Seven, Plus or Minus Two. In his research, Miller argued that the capacity of short-term memory is limited to about seven items, give or take two. This conclusion was based on various experimental findings that suggested the average number of items people could hold in their short-term memory was around seven.
Miller’s theory is supported by several pieces of evidence. For instance, in memory span tasks, participants are usually able to recall between five and nine digits, letters, or words when presented in a random order. This finding suggests that the span of short-term memory typically falls within the range of 5 to 9 items, reinforcing Miller’s claim of seven as an optimal number.
Additionally, research has shown that chunking—grouping information into larger, meaningful units—can help people overcome this limit. For example, a person might find it easier to remember a string of 10 digits if they are grouped into chunks like 123, 456, and 789. This process of chunking reduces the number of individual items in memory, making it easier to hold the information.
While Miller’s concept of seven is widely cited, later research has shown that the exact capacity can vary slightly depending on the type of information being remembered and the individual. However, the idea of a limited capacity for short-term memory and the rule of thumb of seven remains influential in the field of cognitive psychology.