The average male life expectancy in 1900 was 46. However, a wide range of factors, including healthier living environments, and medical and technological advances, have led to an additional 33 years, allowing those born in the U.S. to live an average of 79 years. This rising life expectancy has led to delays in cognitive impairment as well, according to a new European study, which found that elderly people over 80 during the late 2000s had relatively equal mental health when compared to those under 80 during the late 1990s.

What is the Flynn Effect?

“People are better educated than they used to be, their economic wellbeing may be better compared to previous groups,” Dallas Anderson, who studies dementia at the National Institute on Aging, told Reuters. “All these various factors working together lead to an improved situation” in general health for those who are considered to be of old age. These factors, which comprise an overall better situation — namely, from living in developed countries — for elderly people collectively contribute to what’s known as the Flynn effect.

The Flynn effect is largely based on a trend in which subsequent generations tend to have higher intelligence quotients (IQs). In the context of aging, it purports that subsequent generations have improved cognitive function into old age, the researchers said. The trend parallels the rising life expectancy, while also having wide implications for dementia research, which scientists continuously investigate in order to find ways to diagnose Alzheimer’s disease and related disorders at a pre-dementia stage.

Alzheimer’s disease is the most common cause of dementia in older people — symptoms begin to appear after age 60 — affecting nearly 5.1 million Americans, according to the National Institutes of Health. It’s still unclear how the disease develops in the brain, however. People with Alzheimer’s typically have either abnormal deposits of clumps, known as amyloid plaques, or tangled fibers, known as neurofibrillary tangles, in their brains, which formed years before symptoms emerged.

Cognitive Function In Today's Elderly Outshines Yesterday's

For the study, the researchers were interested in seeing how age and cognitive health were affected over time. They looked at data on 204 French elderly patients who participated in cognitive tests between 1991 and 1997 and compared their scores to those of 177 elderly patients, of similar age, who took the same tests in 2008 and 2009. The results showed that those who took the tests in the 2000s had overall higher scores. Digging deeper, participants who were under 80 years old performed better during both time periods than those over 80. However, participants under 80 years old in the 1990s sample performed similarly to those over 80 in the 2000s sample.

“Our findings are concordant with other studies showing that later born cohorts have better cognitive function than do earlier born cohorts,” the researchers wrote, adding that the Flynn effect (FE) might not correspond to higher IQs as theorized. “The FE might only reflect the increase of resources enabling individuals to better cope with challenging cognitive situations.”

The findings, Anderson said, are likely happening in the U.S. as well. But before generalizing the findings onto other countries, it’s important to understand the social advantages France has, Louis Bherer, who studies cognitive decline at Concordia University in Montreal, told Reuters. “France is a country in which education is free and open to everyone, and where everyone has access to free medical care,” he said.

Still, with dementia cases on the decline in the U.S., it’s possible that Anderson is right. “The idea that some people will get extra years of healthy living before they get demented, that’s important,” he told Reuters. “When you look at it from a public health perspective, it’s huge.”

Source: de Rotrou J, Wu Y, Mabire J, et al. Does Cognitive Function Increase over Time in the Healthy Elderly? PLOS One. 2013.