30-Second Psychology: The 50 Most Thought-provoking Psychology Theories, Each Explained in Half a Minute - Christian Jarrett 2011

Broadbent’s bottleneck
Thoughts & Language

In a crowded cocktail party, dozens of people might be speaking at the same time. Yet most of us are able to follow a single conversation while ignoring all the others. How do we do it? Research by the British scientist Colin Cherry in the 1950s showed that we separate out individual voices by focusing on key characteristics - the speaker’s gender, location and pitch. In 1958, British psychologist Donald Broadbent took this work to a new level with a theory of how the entire brain processes information. Up until then many psychologists believed that humans could only process one thing at a time. Broadbent showed that people could hear and comprehend more than one set of sounds simultaneously - provided they were simple enough. In a classic experiment, Broadbent asked people to listen to two sets of digits (such as ’659’, ’842’, and so on), one set played in each ear. Even though the numbers were played at the same time, listeners grouped the digits played through each ear rather than mixing them together. However, once the signals become too complex, a ’bottleneck’ forms, making the signals impossible to manage simultaneously, which is part of the reason it’s dangerous to drive while talking on the phone or texting.

3-SECOND PSYCHE

We are constantly bombarded with sounds, sights and other sensations - yet we can make sense of it all by focusing on small chunks of information.

3-MINUTE ANALYSIS

Broadbent’s original theory said signals that didn’t make it through the bottleneck were simply lost. However, in i960, British psychologist Anne Treisman noted that Broadbent’s theory couldn’t account for the fact that people engrossed in complex tasks could still respond to the sound of their names. Treisman argued that unprocessed signals were actually retained, allowing especially dramatic or important signals to gain our attention.

RELATED THEORIES

WATSON’S BEHAVIOURISM

THE COGNITIVE REVOLUTION

THE LAKE WOBEGON EFFECT

MILLER’S SEVEN

3-SECOND BIOGRAPHIES

DONALD BROADBENT

1926—1993

COLIN CHERRY

1914—1979

ANNE TREISMAN

1935—

30-SECOND TEXT

Dave Munger

If we didn’t have some kind of filter, we’d be caught in a perpetual storm of sensory information.