A new study has shown that our mental speed does not change substantially over decades, according to Science Daily. Mental speed is the speed at which we can deal with issues that require rapid decision-making.

Psychologists at Heidelberg University, who conducted the study, have concluded that our cognitive information processing speed remains largely stable over decades.

The researchers, including Dr. Mischa von Krause and Dr. Stefan Radev, evaluated over a million participants using a large-scale online experiment and found that the mental speed remains largely stable between the ages of 20 and 60. After 60, it only deteriorates.

Dr. von Krause said, “The common assumption is that the older we get, the more slowly we react to external stimuli. If that were so, mental speed would be fastest at the age of about twenty and would then decline with increasing age.”

When evaluating the data, Dr. von Krause and his tea, noted that, on average, the response times of the participants rose with increasing age. However, with the aid of a mathematical model, they were able to show that this phenomenon was not due to changes in mental speed, per Science Daily.

“Instead, we think that older test subjects are mainly slower because they reply more cautiously and concentrate more on avoiding mistakes,” explained Dr. von Krause.

The researchers also found that motor execution speed declines during the course of adult life, as older participants needed longer time to press the appropriate key after finding the right answer.

Another key finding of the study was that the cognitive information processing speed progressively declined among participants who were above the age of 60.

Dr. von Krause said, “It looks as though, in the course of our life, we don’t need to fear any substantial losses of mental speed — particularly not in the course of a typical working life. Generally speaking, we should also note that the test subjects in all age groups included individuals with high and low mental speeds. Our results relate to the average trend.”

The study was published in the journal Nature Human Behaviour. The German Research Foundation (DFG) funded the study.