In general white-collar jobs have been cited as lending themselves better to continued working at older ages than more physically demanding jobs, but age still catches up to white-collar workers, possibly more quickly and more seriously than they would expect, a study has said.

The increasing share of white-collar work in the economy as a whole, a trend reflected in the federal workforce, has been cited as helping employees to continue on the job longer overall than in the past–which increasing numbers say they want to do, for financial or personal reasons.

The report by the Center for Retirement Research examined a system of rating 52 abilities that are important to a job, on a scale of 1 to 5 for their importance to a particular occupation.

It found that that “crystallized” cognitive abilities, such as vocabulary, “tend to accumulate well into an individual’s sixties and even seventies. Thus, skills like oral and written comprehension and math¬ematical reasoning are often maintained throughout a career. Workers in white-collar occupations that rely on these abilities may be able to work longer without notice¬able declines.”

In contrast, “fluid” cognitive abilities, such as episodic memory, working memory, and inductive and deductive reasoning — which people need to acquire new information and make decisions — “steadily decline with age starting in a worker’s twen¬ties or thirties.”

In addition, it said, for white-collar jobs that also rely on quick reaction time, and fine motor skills — it gave as examples licensed practical nurses, photographers and pilots — retirement tends to occur relatively early.

“Thus, the notion that all white-collar workers can work longer or that all blue-collar workers cannot is too simplistic. Instead, it is important to consider the particular abilities required by an occupation and whether these abilities decline significantly by the time workers reach typical retirement ages,” it said.