November 18th 2011: Recent evidence suggests that our perceptions of ageing and age impact how we experience age. Yale University psychologist Becca Levy has taken an interest in these questions. Not only has she found that members of cultures where ageing is viewed more positively fare better than older people in general populations, she also found that people themselves perform better when primed with positive words about ageing.
She tested healthy subjects that were 90 and over. Then she flashed positive words about aging like “guidance,” “wise,” “alert,” “sage” and “learned” and tested them again. Their memories were better and they even walked faster. Next, she flashed negative words like “dementia,” “decline,” “senile,” “confused” and “decrepit.” This time, her subjects’ memories were worse, and their walking paces slowed.
In another study, she found that people who had more positive views about aging were healthier and lived longer lives. They lived an average of 7.6 years longer than those of a similar age who did not hold such views, and even had less hearing loss when their hearing was tested three years after the study began. The result persisted when the investigators took in account the participants’ health at the start of the study, as well as their age, gender, and socioeconomic status.
On the Dependency Ratio and the Need for New Measures
Since lifespan is increasing and people are living longer, healthier lives we need to revisit the so-called “dependency ratio”. Often used by policy makers to measure just how burdensome the ageing population will become, the dependency ratio considers that everyone 65 years and older is dependent on everyone 65 years and under. Dr. Warren Sanderson, who has proposed a new measure, says, “those measures are based on fixed chronological ages and this can generate misleading results”.
Policy makers would do a better job of solving the problem of a shrinking work force to pay for the increasing health-care costs if they first defined the problem accurately. They use the “dependency ratio” – the number of people over 65 divided by those under 65 – which ignores improving health and longevity.
Putting healthy people into the category of old age dependents is not only anachronistic, but leads to bad public policy. This scares many people about the speed of aging and leads to apocalyptic visions about the health-care system.
If instead, the dependant population is defined by the projected incidence of ill health and other causes of disability, then the ratios are much more optimistic and instead of escalating, the trend lines are nearly flat in North America. Change is necessary but if we’re going to cite science to make policy, then let’s start with good science.