Ramscar et al, (2014) did research to find that a decline in…

Ramscar et al, (2014) did research to find that a decline in information processing speed is not necessarily indicative of a decline in cognitive capability. They do not deny that older adults take longer to process information in the manner indicated by the tests, only that this is the result because

Exactly when fluid intelligence begins to decrease is an obj…

Exactly when fluid intelligence begins to decrease is an object of some debate in the academic literature. Some date it from the late 20s, others somewhat later, around the mid 40s. There are of course differences between individual persons. Assuming Jim is in his late 50s, what kind of cognitive information will he likely process in slower fashion that when he was 20?