This makes sense. Most Paleolithic members of the species Homo sapiens were dead by age forty, so there hasn't been much selection pressure to favor human beings preserving health or their faculties much past that age. I'm living on borrowed time, being almost twice as old as the headlined age. On the other hand, some people decline more or less rapidly, and from a better or worse base, so fifty-year-olds can still outsmart twenty-seven-year-olds in specific cases.

"However, the report published in the academic journal Neurobiology Of Ageing, found that abilities based on accumulated knowledge, such as performance on tests of vocabulary or general information, increased until at the age of 60."

Live life to the fullest while you can appreciate it.