Speed of processing has been a major explantory varialbe for enhanced cognitive performace during development.
Specifically, there is a exponential increase in the speed of processing from early childhood up through the teenage
years. This speed of processing is associated with enhanced cognitive performance. For example, imagine how the
number of words in a recall test might increase if increased speed of processing allowed for more word rehersal.
Speed of processing increases from early childhood up into the twenties and begins to show a significant decline
by the fifties.
Similarly, there are reported medium sized correlations between speed of processing and fluid intelligence.
Currently, the first part of the Trails test can be considered to provide an assessment of speed of processing.