Stanford researcher Laura L. Carstensen, Ph.D., directs the Stanford Center on Longevity. In this second installment of a two-part series, she responds to questions on some of the key areas of research regarding the psychological aspects of aging.
Q: How does aging affect expertise and life knowledge?
A: We know that what has been called “fluid intelligence” (such as speed of information processing) declines over time, but “crystallized intelligence” (such as emotional expertise and life knowledge) grows as we age.
There’s ample evidence that older adults are as good as – and in some ways better than – younger adults at regulating their emotions. This likely reflects enhanced knowledge about oneself and other people. My research shows that when older adults experience negative emotions, these feelings last for shorter periods than for younger adults.
Interesting insight comes from neuroimaging research led by Gregory Samanez Larkin, which shows that older adults show less brain activity than younger adults while anticipating monetary losses – but not while anticipating gains. That would suggest that they’re less ruffled by the possibility of financial loss than younger people.
Knowledge is hard to research because it is so individualized. My expertise, for example, in psychology is entirely different from the expertise that an engineering colleague may have. From a research perspective, it’s difficult to measure and quantify knowledge across individuals. Because of this, we tend to use more general measures of things like vocabulary and cultural knowledge, measures that surely underestimate specialized knowledge.
Q: Why is it important to study knowledge?
A: Life knowledge and expertise are the products of information processing. The efficiency of processing new information is somewhat degraded with age, but learning continues. The longer we live, the more experience we have. Absent diseases, like Alzheimer’s, there is nothing about aging that makes people lose knowledge. Consequently, it continues to grow into advanced ages. The more we know about the world, the better we navigate it.
Older scientists are usually the most knowledgeable in their disciplines. Older symphony conductors are the most renowned. Congress is filled with older people who understand how bills are passed and have a rich knowledge base about our country’s history. As much as people criticize Congress, I think most people would rather have a group of 70-year-olds govern the nation than 20-year-olds.
In addition, knowledge helps us to compensate for some of the losses we see. For example, when you can’t retrieve a word you want from memory, having a large vocabulary allows you to deliver your message using different words.
Wisdom is a term that refers to knowledge that goes beyond a store of facts and is different from how fast you can solve a new puzzle. It is considered practical knowledge about the human condition. Along with an understanding of how to accomplish goals, it includes an understanding of the relative nature of knowledge and the need to consider circumstances before acting. “Right” and “wrong” shift to shades of gray. Experience does not ensure wisdom, but it affords the opportunity for wisdom to emerge. Research suggests that wisdom peaks in middle age and does not decline in advanced age.
Understanding the strengths of older minds will help societies best use the resources older people offer.
Q: Are older adults among the most stable and mentally healthy of all the age groups?
A: Yes, research on mental health and well-being has revealed something that’s been called the “well-being paradox.” The objective realities of old age can be daunting – weaker physical health, a decline in cognitive function and independence, and often the deaths of close friends. However, older people experience a remarkably high level of subjective well-being.
Not only do they register life satisfaction levels as high as those of younger people, but they also experience less negative emotion and less interpersonal conflict than younger adults. Mental illness, such as depression and anxiety disorders, is less common among the elderly than it is among younger adults.
All this is good news – but only for those who are aging normally. Whereas most psychiatric disorders decline with age, by definition dementia is a brain disease of old age. With a terrible disease such as Alzheimer’s, for example, everything changes. There is a lot of research devoted to Alzheimer’s because there’s a large rise in the incidence of the disease with each decade of life – indeed, more than one-third of all people who reach age 90 have it.
At the moment, there is no cure for Alzheimer’s, although medication can postpone its symptoms. Lots of scientists are aiming to find ways to detect the disorder as early as possible. Stanford researchers Ruth O’Hara and Michael Greicius are among those using brain imaging and other techniques to discover early signs of Alzheimer’s. In addition to their work in early detection, Jerome Yesavage and Jared Tinklenberg are also investigating drug treatments.
The Stanford Center on Longevity provided content for this article. For more information, visit longevity.stanford.edu.