Why does our language ability remains resilient and how does it shape our lives？The new book "Changing Minds: How Aging Affects Language and How Language Affects Aging," written by Roger Kreuz (Associate Dean and Director of Graduate Studies in the College of Arts and Sciences and Professor of Psychology at the University of Memphis) and Richard Roberts (a Foreign Service Officer currently serving as the Public Affairs Officer at the US Consulate General in Okinawa, Japan), is forthcoming in October, published by The MIT Press.

In this new book, the authors examine how aging affects language—and how language affects aging. They write that we acquire our native language, seemingly without effort, in infancy and early childhood. Language is our constant companion throughout our lifetime, even as we age. But compared with other aspects of cognition, language seems to be fairly resilient to the process of aging.

Language and aging is a ‘two-way street’

SSCP: Many writers achieve outstanding achievements at an older age, such as the Nobel Prize in Literature winner Toni Morrison. Is there an explanation for this?

Roger Kreuz: When Toni Morrison died on Aug. 5, the world lost one of its most influential literary voices, but Morrison wasn’t a literary wunderkind. The Bluest Eye, Morrison’s first novel, wasn’t published until she was 39. And her last, God Help the Child, appeared when she was 84. Morrison published four novels, four children’s books, many essays and other works of nonfiction after the age of 70.

Morrison isn’t unique in this regard. Numerous writers produce significant work well into their 70s, 80s and even their 90s. Herman Wouk, for example, was 97 when he published his final novel, The Lawgiver.

Such literary feats underscore an important point: Age doesn’t seem to diminish our capacity to speak, write and learn new vocabulary. Our eyesight may dim and our recall may falter, but, by comparison, our ability to produce and to comprehend language is well preserved into older adulthood.

In our forthcoming book, my co-author and I highlight some of the latest research that has emerged on language and aging. For those who might fear the loss of their language abilities as they grow older, there’s plenty of good news to report.

SSCP: Can you introduce the main content of the new book? What inspired you to write this new book?

Roger Kreuz: Our book reviews research on language ability across the adult lifespan, from younger through older adulthood. Most people are aware that the aging process causes changes in our language ability — as we get older, we may not be able to hear or to see as well, and we may have a harder time recalling words or the names for things. However, some language functions improve with age. And the relationship between language and aging is a ‘two-way street’: language also influences the aging process. We make the case that engagement with language throughout one’s life has benefits for health and even one’s longevity.

Specifically, we report that what appear to be changes in an older person's language ability are actually the result of declines in other cognitive processes as memory and perception. Some language abilities, including vocabulary size and writing ability, may even improve with age. And certain language activities—including reading fiction and engaging in conversation—may even help us live fuller and healthier lives. The book explains the cognitive processes underlying our language ability, exploring in particular how changes in these processes lead to changes in listening, speaking, reading, and writing. We discuss, among many other things, the inability to produce a word that's on the tip of one's tongue, and suggest that the increasing incidence of this with age may be the result of a surfeit of world knowledge. For example, older people can be better storytellers, and (something to remember at a family reunion) their perceived tendency for off-topic verbosity may actually reflect different communicative goals.

Older adults have also been shown to have larger vocabularies than younger adults. This makes sense if one considers that older adults benefit from several additional decades of practice with reading and writing. Similarly, older adults are better at understanding idiomatic expressions, such as “letting the cat out of the bag” for revealing a secret. Once again, older adults are benefitting from more years of exposure to their language.

‘Missing middle’ in language research

SSCP: What are the blind spots in the past research on language and aging?

Roger Kreuz: Most language researchers focus on children or older adults. We wanted to provide interested readers with a roadmap of what happens during the middle part of life’s journey. Does our ability to spell words correctly increase or decrease over time? How about our ability to tell an interesting story, or to acquire a second language? What do we know about writer’s block? Such topics have received less attention, and we wanted to highlight the research that addresses such questions.

For example, most studies involving language are focused on children and college-aged students, since they belong to groups that are relatively accessible to researchers. At the other end of the age spectrum, people who are retired are frequently recruited for research studies. Among other goals for the book, we wanted to highlight research exploring the language abilities of those aged 20-60, who constitute what we refer to as the “missing middle” in language research.

SSCP: Which examples impressed you during the research？What predictions can be made about people's cognitive ability based on their language ability？

Roger Kreuz: One study, for example, found that older adults living in a retirement community near Chicago had an average vocabulary size of over 21,000 words. The researchers also studied a sample of college students and found that their average vocabularies included only about 16,000 words. In another study, older adult speakers of Hebrew – with an average age of 75 – performed better than younger and middle-aged participants on discerning the meaning of words.

On the other hand, our language abilities sometimes function as a canary in the cognitive coal mine: They can be a sign of future mental impairment that may appear decades before such issues manifest themselves.

In 1996, epidemiologist David Snowdon and a team of researchers studied the writing samples of women who had become nuns. They found that the grammatical complexity of essays written by the nuns when they joined their religious order could predict which sisters would develop dementia several decades later. (Hundreds of nuns have donated their brains to science, and this allows for a conclusive diagnosis of dementia.)

While Toni Morrison’s writing remained searingly clear and focused as she aged, other authors have not been as fortunate. The prose in Iris Murdoch’s final novel, “Jackson’s Dilemma,” suggests some degree of cognitive impairment. Indeed, she died from dementia-related causes four years after its publication.

Don’t put down that book

SSCP: “Language mastery is a lifelong journey”; what do you mean by that?

Roger Kreuz: We argue that language learning doesn’t end when a person leaves school. We continue to acquire the meanings of words and benefit from practicing our writing skills. Although our language abilities aren’t formally assessed after we complete our educations, research by psychologists and gerontologists does support the idea that our knowledge of and fluency in using language continues to expand across our lifetimes.

SSCP: How important is writing and reading for elderly people?

Roger Kreuz: Our ability to read and write can be preserved well into older adulthood. Making use of these abilities is important, because reading and writing seem to prevent cognitive decline. Keeping a journal, for example, has been shown to substantially reduce the risk of developing various forms of dementia, including Alzheimer’s disease. Reading fiction, meanwhile, has been associated with a longer lifespan.

A large-scale study conducted by the Yale University School of Public Health found that people who read books for at least 30 minutes a day lived, on average, nearly two years longer than nonreaders. This effect persisted even after controlling for factors like gender, education and health. The researchers suggest that the imaginative work of constructing a fictional universe in our heads helps grease our cognitive wheels. Language is a constant companion during our life journey, so perhaps it’s no surprise that it is interwoven into our health and our longevity. And researchers continue to make discoveries about the connections between language and aging. For example, a study published in July 2019 found that studying a foreign language in older adulthood improves overall cognitive functioning. A thread seems to run through most of the findings: In order to age well, it helps to keep writing, reading and talking. While few of us possess the gifts of a Toni Morrison, all of us stand to gain by continuing to flex our literary muscles.

SSCP: What are your advices to our audience on how to use their brain and language?

Roger Kreuz: The research that we review strongly suggests that engagement with language can be helpful throughout adulthood. Writing about trauma, for example, has been shown to confer health benefits. And as I noted earlier, older adults who continue reading fiction have been shown to have longer lives than their non-reading counterparts. The mental effort required to create fictional universes in our heads seems to confer substantial cognitive benefits. We encourage people to keep reading, keep writing, and keep talking!

Roger Kreuz is Associate Dean and Director of Graduate Studies in the College of Arts and Sciences and Professor of Psychology at the University of Memphis. He is the coauthor (with Richard Roberts) of "Becoming Fluent: How Cognitive Science Can Help Adults Learn a Foreign Language," "Getting Through: The Pleasures and Perils of Cross-Cultural Communication," and "Changing Minds: How Aging Affects Language and How Language Affects Aging" (all published by the MIT Press).

Richard Roberts is a United States Foreign Service Officer currently serving as the Public Affairs Officer at the US Consulate General in Okinawa, Japan.