Psychology › Thinking, memory & biases › Memory and how it works
Working memory
1974 (Baddeley & Hitch)· Theory or model
Well replicatedStrong, repeated evidence.
Working memory is the mind's small mental workspace, holding and manipulating a few pieces of information for seconds.
See it on the Psychology map →What it says
Alan Baddeley and Graham Hitch proposed in 1974 that short-term memory is not a holding bin but an active workspace. Their model has a 'central executive' directing attention, a 'phonological loop' for words and sounds (repeating a phone number), and a 'visuospatial sketchpad' for images; an 'episodic buffer' was added in 2000. Capacity is small: George Miller's 1956 'seven plus or minus two' is now thought closer to about four chunks.
Why it matters
Its capacity predicts reasoning, reading and problem-solving ability, and its overload explains why complex decisions and mental math fail under stress or distraction.
Think of it like
Like a desktop versus the file room: only a few papers fit on the desk at once.
The evidence
Well replicated. Dual-task experiments show words interfere with words, and images with images, more than with each other; brain imaging and patient studies support separate parts.
Open questions
Whether 'brain training' of working memory raises intelligence: large reviews find gains on the trained tasks but little transfer to everyday abilities.
Connections (4)
▸Attention and its limits controls what enters Working memoryWell replicated
The connection
Attention acts as the gatekeeper: what you attend to gets into working memory, and what you ignore mostly does not. In Baddeley's model the 'central executive' is essentially an attention controller, and people who block distractions better tend to have higher working-memory capacity.
Who showed it and when
Baddeley and Hitch in Britain from 1974; Randall Engle's lab at Georgia Tech in the 1990s and 2000s on attention control and capacity.
The evidence
Experiments show distractors using up memory slots, and brain recordings by Edward Vogel and colleagues (2005) show low-capacity people store more irrelevant items.
Open questions
Whether working memory and attention are truly separate systems or two faces of one limited resource is still argued.
▸Working memory is the short-term workspace of Memory and how it worksWell replicated
The connection
Working memory is memory's active front end: information is held and processed there before it is stored long-term, and long-term memories are pulled back into it when needed. Working with ideas for meaning there, rather than just repeating them, makes them more likely to last.
Who showed it and when
Built on Atkinson and Shiffrin's short-term store (1968) and Baddeley and Hitch's 1974 model, in the US and Britain.
The evidence
Lab studies show items processed for meaning are remembered far better later (Fergus Craik and Robert Lockhart's 'levels of processing', 1972).
Open questions
Some models, such as Nelson Cowan's, treat working memory as simply the currently activated part of long-term memory, not a separate store.
▸Working memory correlates strongly with Intelligence and the g factorWell replicated
The connection
Working memory is the mental workspace that holds a few items while you use them. People with larger capacity tend to score higher on reasoning tests; some analyses put the correlation with fluid intelligence around 0.7, suggesting both draw on the ability to control attention.
Who showed it and when
Key studies include Patrick Kyllonen and Raymond Christal's 1990 US Air Force research and a 2005 analysis by Michael Kane and colleagues.
The evidence
Large test batteries consistently show the correlation. But training that boosted working memory did not raise intelligence, according to 2013 and 2016 meta-analyses of brain-training studies.
Open questions
Is working memory a cause of intelligence, or simply another measure of the same underlying ability? Researchers still disagree.
▸Working memory replaced the short-term store in Memory systems: short-term, long-term, episodic, proceduralWell replicated
The connection
Atkinson and Shiffrin's 1968 model had a single short-term store acting as a waiting room for long-term memory. Baddeley and Hitch found people could hold several digits and still reason fairly well, which one store could not explain, so they replaced it with a multi-part working memory.
Who showed it and when
Atkinson and Shiffrin at Stanford, 1968; Baddeley and Hitch at the University of Stirling, Scotland, 1974; Tim Shallice and Elizabeth Warrington's patient K.F., 1970.
The evidence
Dual-task experiments, and patients like K.F., who had very poor short-term memory yet normal long-term learning, contradicted the single-store model.
Open questions
Parts of the old model, such as rehearsal moving items into long-term memory, are debated rather than fully discarded.