Ever wondered why is one person's IQ higher than another's? Well, a new research has answered this question.
According to a University of Oregon study, more items stored in short-term memory is linked to greater fluid intelligence, as measured in IQ tests.
The resolution of those memories, while important in many situations, shows no relationship with fluid intelligence.
Previous research has shown that capacity in short-term memory is a reliable predictor of an individual's IQ.
However, the new study has tried to link the memory capacity with fluid intelligence.
"The number of things people can remember is robustly correlated with fluid intelligence-the larger number remembered, the higher the IQ," said Edward Awh, a member of the Oregon Visual Working Memory and Attention Lab.Clarity relates to how well a person can detect small changes," said lead author Keisuke Fukuda.
This clarity, Fukuda and Awh noted, is indeed important but is a reflection of a person's experience in specific domains of perception.
Fukuda put 79 undergraduate students through a series of experiments in which either four or eight objects were shown on a screen for an instant. After a one-second blank screen, one item was returned and the subject asked whether that object had been in a location previously.
By examining the ability to detect large and small changes in the memorized items, Fukuda was able to get estimates of both the number of items maintained in memory, as well as the resolution or clarity of those memories. These aspects of memory were then related to the subjects' scores on tests of fluid intelligence.
The discovery that clarity doesn't factor into a person's IQ score doesn't suggest that memory resolution is unimportant, noted the researchers.
The importance of clarity or resolution of things remembered is indeed vital, for example, to a radiologist studying images of a patient's internal organs with potential disease conditions.
The findings were published in the journal Psychonomic Bulletin and Review.