The limitations of the brain in decision-making
October 26th, 2009 // 11:02 am @ David Phillips
In 1956, George A. Miller completed a research project that looked at the number of items that could be held in the mind at one time. It was called The Magical Number Seven, Plus or Minus Two published in Psychological Review. The maximum, he found, was seven, plus or minus two. As a result of this research, many people have lived frustrated because they can’t hold that much information in mind. However, it appears Miller was wrong, or at least often misrepresented.
A wide survey of research by Nelson Cowan in 2001 found that the number of items that you can hold in mind is likely not seven. It’s more like four. Yet this even depends on the complexity of the four items. Four numbers is not a big problem. Four long words gets more difficult. Four sentences creates chaos unless the sentences are very familiar such as a memorized prayer or an advertising jingle. In addition, a study by Brian McElree at NYU found that the number of chunks of information you can remember accurately, with no degradation, is one. Yes, you read that right: one! Long-term memory is enormous. Short-term memory, however, is extremely limited.
When making decisions, this can overwhelm us. We have to process large and often complex amounts of information so that a decision can be made. What happens during that process has even spawned an entire field of study called relational complexity. Working memory limitations are best defined in terms of the complexity of relations that can be processed in parallel. Complexity is defined by the number of dimensions, or sources of variation, that are related. Empirical evidence indicates that human adults are limited to processing four relations in parallel. More complex concepts are processed by segmentation (breaking tasks into serially processed components that do not exceed processing capacity) or conceptual chunking (”collapsing” representations to reduce their dimensionality, but at the cost of making some relational information inaccessible). [1] Relational Complexity thus shows that the fewer variables you have to hold in mind, the more effective you are at making decisions.
This is a huge challenge for a lot of people. This issue is not simply an avalanche of information that comes our way, but we have to process that information and make decisions based on it. The more information, the less effective the decision-making process is and the less effective those decisions will be.
NOTES:
[1] Processing Capacity Defined by Relational Complexity: Implications for Comparative, Developmental, and Cognitive Psychology by Graeme S. Halford, University of Queensland, William H. Wilson, the University of New South Wales and Steven Phillips from Electrotechnical Laboratory
Category : Books & Personal Development