13.3 Cognition in Middle Adulthood

Formal and Postformal Thought

According to Piaget’s theory of cognitive development, the final stage of cognition is formal operational thought, characterized by the capacity for hypothetical, deductive, and abstract thinking. It emerges in adolescence and continues throughout adulthood, though Piaget himself and others have argued that demonstration of some aspects of formal operational thinking is not universal among adults and may be most evident in an adult’s area of expertise (Kuhn, 2008; Piaget, 1972). Other researchers have argued that some adults develop beyond formal operational thinking to a stage known as postformal thought (Perry, 1968). In postformal thought, the intuitive thinking that comes from experience is combined with the logic of formal operations to produce a cognitive style known as relativism. It is recognized in relativism that some problems or dilemmas may have more than one viable solution, depending on a person’s perspective and priorities.

The differences in cognition between formal and postformal thought are subject to debate, and the evidence is unclear as to whether this style of thinking qualifies as a more advanced stage and whether it is typical of adult thinking (Blanchard-Fields, 2001). Whatever the case, changes in cognition that occur in middle adulthood are best understood as changes in the way individuals perceive and process information, rather than as overall advancements or declines. It is possible that the use of relativistic thinking is, in fact, an outcome of the experiences and wisdom accumulated from the lived experience of adults over the lifespan.

Memory and Problem-Solving

Perhaps the most noted research in the understanding of cognition over the course of adulthood is the Seattle Longitudinal Study. The study was initiated by K. Warner Schaie in 1956,, and since that time, it has assessed the psychological and cognitive development of 6,000 adults with ages ranging from 22 to over 100 years old (Seattle Longitudinal Study, 2024). The longitudinal nature of this study provides a great advantage over the previous cross-sectional studies in understanding individual changes in cognitive development because cross-sectional approaches were confounded by generational differences known as cohort effects. The results from the Seattle Longitudinal Study provide insight into changes in adult cognition as people age.

The longitudinal study found that different types of memory and cognitive processes exhibit different trajectories with age. Verbal and semantic memory—long-term recall of words or concepts—remain consistent and even somewhat increase until the end of middle adulthood (Hedden & Gabrieli, 2004; Park et al., 2002; Schaie, 1996). Working memory—the ability to process new and previously encoded information during short-term cognitive tasks—becomes somewhat less efficient as processing speed and short-term storage capacity peak in young adulthood and gradually decline as we age (Park et al., 2002; Rhodes et al., 2019; Schaie, 2003). However, effective memory strategies and engaging in physical exercise can improve working memory ability in middle adulthood (Hertzog et al., 2019; Liu & Lachman, 2019).

Practical problem-solving on everyday tasks, such as purchasing goods or figuring out a bus schedule, shows improvement in middle adulthood, largely from accumulated experience (Chen et al., 2017). Another advantage of middle adulthood is the development of expertise over the course of many years in a career or field of interest. Through continued deliberate practice and engagement, experts in a field can use automatic processing, better strategies, and more creativity in problem-solving for their domain of experience (Ericsson, 2020).

A model of physical and cognitive aging proposed by Nancy Denney suggests that the development of physical abilities and the development of cognitive abilities both follow a similar pattern, with an early adulthood peak and gradual decline (Denney, 1984). Individuals can influence their own peaks by prioritizing the practice of particular skills. Those skills that are not practiced and that therefore peak at lower levels will decline sooner during the aging process. For example, more time spent in formal education results in higher cognitive functions in middle adulthood (Lövdén et al. 2020). As you find in Chapter 15 Physical and Cognitive Development in Late Adulthood (Age 60 and Beyond), diagnosis of cognitive declines is based on comparing individual performance to a universal average, and thus those with higher peaks will take longer to decline to a level at which a diagnosis of cognitive impairment may be made.

Intelligence and Wisdom

Psychologists have conceptualized intelligence through a variety of theories that are useful in framing how the development of intelligence may vary, depending on how it is defined and measured. As discussed in 7.3 Intelligence in Middle Childhood, Robert Sternberg’s triarchic theory of intelligence proposes that intelligence can be divided into three abilities: analytical, creative, and practical. Sternberg argued that while each of these intellectual components allows people to adapt to changing life demands and circumstances, how they are applied and the priority that they have in our lives will change with age (Berg & Sternberg, 1985). For example, analytical intelligence uses academic knowledge and computation, which can be applied in middle adulthood within a given career or field of interest. Practical intelligence is needed for solving everyday challenges, and as research has shown, adults exhibit improvement in this type of problem-solving as a result of lived experience (Chen et al., 2017). The innovative problem-solving that belies creative intelligence is often built on existing expertise in a given area, and as you have learned, adults continue to increase their semantic memory and expertise throughout middle adulthood.

The value of accumulated knowledge or wisdom in supporting the triarchic domains of intelligence may remind you of Raymond Cattell’s theory of intelligence, also introduced in 7.3 Intelligence in Middle Childhood. Sternberg and colleagues agree and assert that their theory of how intelligence develops in adulthood is certainly compatible with that of Cattell (Berg & Sternberg, 1985). Cattell’s theory of intelligence suggests two primary components of intelligence. Crystalized intelligence consists of accumulated abilities in long-term memory, such as knowledge and vocabulary. Because crystallized intelligence is developed through experience, it exhibits continuous and steady increases throughout the lifespan. Fluid intelligence, which is the ability to reason and solve novel and abstract problems, peaks in early adulthood, remains relatively steady in the middle adult years, and declines as individuals enter older adulthood (Figure 13.11).

Figure 13.11 Adults in middle adulthood demonstrate gradual decrease in fluid intelligence and gradual increase in crystallized intelligence. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

There are also generational changes in performance on intelligence tests, known as the Flynn effect. The Flynn effect occurs when newer generations perform better on intelligence tests than previous generations. This doesn’t mean, however, that younger generations are more intelligent than their older counterparts. According to James Flynn, who discovered the phenomenon, explanations include improved access to nutrition and education over time that promote physical and cognitive growth and well-being (Flynn et al., 2012).

Cultural context influences how people think about and apply intellectual abilities (Benson, 2003; Warne, 2020). While Western cultures often perceive intelligence as an analytical skill that helps us to categorize concepts and form arguments, East Asian cultures are more likely to emphasize the interpersonal implications of intelligence and how it helps us to effectively interact with others (Nisbett, 2004; Yang & Sternberg, 1997).¹ Different cultures have also been found to vary in the extent to which they foster and value practical, as opposed to academic, intelligence (Sternberg et al., 2001).

Wisdom is frequently associated with age, and like many cognitive abilities, it develops over time. Like intelligence, conceptions of wisdom may vary cross-culturally, but wisdom is broadly defined by the German psychologist Paul Baltes as “expert knowledge concerning the fundamental pragmatics of life,” a description that incorporates aspects of self-understanding, knowledge, prosocial values, and openness (Bangen et al., 2013). Wisdom can be measured using performance or self-report measurements. Performance measures, such as the Berlin Wisdom Paradigm developed by Baltes and Staudinger (2000), ask respondents to advise fictional characters faced with life decisions: for example, “In reflecting over their life, people sometimes realize that they have not achieved what they had once wanted to achieve. What could a person consider and do in such a situation?” The participant’s level of wisdom is then evaluated based on their response. Self-report measurements, such as the Brief Wisdom Screening Scale (Glück et al., 2013), ask respondents to indicate how much they agree with statements such as, “I can accept the impermanence of things” or “I have grown as a result of the losses I have suffered.”

Research findings about aging and wisdom are complicated. Many aspects of the trait are only marginally predicted by age, if at all (Dong et al., 2023). Across findings, it seems wisdom is less about age and more closely related to applying life experience to difficult life problems or social issues (Figure 13.12). Even personality factors like openness and creativity come into play, though perceptions of the traits associated with wisdom vary cross-culturally. In Western cultures, such as America and Australia, traits such as “experienced” and “knowledgeable” are most closely associated with wisdom. In Eastern cultures, such as India and Japan, wisdom is more closely associated with the social skill of “discretion” (Takahashi & Bordia, 2000).²

Figure 13.12 While wisdom is often associated with age, some research suggests that it is more closely related to applying life experience to difficult life problems or social issues. (credit: “Tenzin Gyatso - 14th Dalai Lama (2012)” by Christopher Michel/Flickr, CC BY 2.0)

Creativity

While young creative minds may be more popularly visible in some domains, such as music and media, people often reach greater moments of creativity in middle age and beyond. A study of famous painters from the nineteenth and twentieth centuries found that these artists typically created their most valuable paintings when they were forty-two years old (Franses, 2013). Creativity is often thought of as only an artistic quality, but it is derived from cognitive abilities that can be applied in several domains, including science. In fact, an examination of scientists who won the Nobel Prize for scientific breakthroughs found that since the year 2000, most prize-winning physicists and chemists were well into middle adulthood when they made their discoveries, with physicists being forty-eight years old on average (Jones & Weinberg, 2011). As we age, we learn what works best for each of our own creative processes, allowing us to maximize individual creativity.

Creativity can be generated by both divergent and convergent thinking. Divergent thinking allows us to develop many solutions to a problem when there is no clear solution (Guilford, 1967). This can mean applying the abilities of fluency, flexibility, originality, and elaboration. If you had to come up with all the things you might do with a traditional red brick, for example, you produce many ideas (fluency), a wide variety of ideas (flexibility), unusual ideas (originality), and add complex details to your ideas (elaboration) (Figure 13.13). Convergent thinking is the creative ability to determine a best solution to produce a desired outcome. In the tale of the “Three Little Pigs” who each construct a house to keep safe from the big bad wolf, the pig who chooses to build his house from bricks (and not straw or sticks) demonstrates convergent thinking.

Figure 13.13 Creativity is the ability to generate a variety of ideas that demonstrate both divergent and convergent thinking. (credit left: “brick wheel stopper” by Kerry Ceszyk/Flickr, CC BY 4.0; credit middle: modification of work “Our new firepit” by Kim Siever/Flickr, Public Domain; credit right: modification of work “Арка, которая задавала стиль всему зданию” by Alexander/Flickr, Public Domain)