Lively youth, lame old people, this is a common prejudice, not only in terms of mobility, but also mental comprehension. An online experiment with more than one million participants by a team led by Mischa von Krause from Heidelberg University now refutes this view: As the working group writes in "Nature Human Behaviour", the speed of cognitive information processing remains largely stable between the ages of 20 and 60. Only then does the mental processing speed decrease.
In the test, the test subjects had to assign the categories "white" or "black" people as well as words to the categories "good" or "bad" by pressing a button. It is an implicit association test (IAT) with which prejudices are to be researched. However, this content did not play a role for their own work, writing from Krause and Co. They used the data record in the sense of a reaction time task in which the duration of cognitive decisions was measured. They then correlated them with the age of the test subjects who were between 10 and 80 years old.
Their reaction time actually increased with age: The average time for a correct answer reached its peak at about 20 years, as previous studies showed. However, this is not due to cognitive decline, writes the team, which comes to a different conclusion with the help of a mathematical model. "In our view, older subjects are slower mainly because they respond more cautiously and concentrate more on avoiding mistakes," says von Krause. One of the reasons why the 20-year-olds were the fastest was that they were most willing to trade accuracy for speed. At the same time, the motor reaction speed decreases: Older test participants simply took longer to press the appropriate button after they had found the right answer.
The highlight of the intellectual processing speed is reached according to Krause and Co at around 30 years; After that, it only decreases very slightly up to the age of 60. The subjects also made fewer mistakes, the older they became, at least until about 60. It is only about the threshold that the average speed of information processing sank progressively, the working group said. "It looks as if we do not have to fear any significant losses in the mental processing speed in the course of our lives - especially not in the course of a typical professional life," says Mischa from Krause.
