Cognitive Development in Adulthood

Definition of Cognitive Development in Adulthood

Cognitive development in adulthood involves the ability to better integrate emotion and logic to make decisions and a decline in the ability to quickly process information. In late adulthood, cognitive development is characterized by neurocognitive disorders, intellectual changes, and memory changes. Chances are that you associate wisdom with being older. A common assumption about aging is that a person becomes wiser as they age.

Wisdom also involves the ability to resolve conflict, make decisions, and handle uncertainty. While some studies suggest that wisdom increases steadily between the ages of 13 to 25 and remains stable until age 75, other studies suggest that adults 70 and older have more wisdom than young adults. Either way, to assume that older adults are wise simply due to their age may be an inappropriate stereotype. The reverse is also true: we shouldn't assume that an older adult doesn't know about something simply because of their age.

The Process of Cognitive Development in Adulthood

Adults go through many changes in cognitive development. The timing of those changes depends on many different factors. The two primary changes in cognitive functioning are related to information processing and intellectual abilities.

Information Processing

As we age, our ability to mentally process information tends to slow down. In addition to slower information processing, memory begins to decline in adulthood as well. Recalling information, in particular, takes a major hit in adulthood. However, recognizing information does not decline as quickly.

Information recall can depend on the type of information and its context. If the information is meaningful in some way, older adults may be able to recall that information more easily. Also, some forms of verbal memory may decline more slowly with age than other forms of memory.

In the laboratory, older adults perform slower in time-based tasks than younger adults. However, outside the lab, older adults and younger adults may perform at about the same level. Finally, older adults sometimes forget certain tasks if they are temporarily delayed or distracted from performing the task.

Intellectual Changes

Information processing is not the only decline in cognitive development in adulthood. Adults also experience intellectual changes as well. There are two types of intelligence: fluid intelligence (logical and abstract reasoning) and crystallized intelligence (factual knowledge and verbal skills). Some intellectual skills can actually improve with age, but others are more likely to decline.

To test the decline of fluid and crystallized intelligence, Schaie's "Seattle Longitudinal Study" used a cross-sectional design to study participants from different age groups as they aged. Schaie (1996, 2006) found that intellectual abilities tend to remain stable throughout early and middle adulthood and begin to decline in late adulthood. Schaie also found that fluid intelligence typically declines at a faster rate than crystallized intelligence.

Stages of Cognitive Development in Adulthood

Cognitive development in adulthood peaks in the mid-20s then slowly declines throughout the rest of life. Piaget’s theory of development suggests that formal operational thinking begins during adolescence and continues throughout life.

Not all psychologists were satisfied with Piaget's cognitive development stages. They felt that another stage should be added after the formal operational stage. Further studies expanded Piaget's theory to include a 5th stage: post-formal operational thinking.

Adults who have reached this stage integrate emotion and logic to make their decisions, but adolescents and young adults tend to make more emotionally-based decisions. Post-formal operational thinking is also more dialectical, meaning that the person considers several different viewpoints rather than just one. Thinking is more flexible and balanced as a result.

Psychologists typically use either a cross-sectional or longitudinal research design to study cognitive development in adulthood. Cross-sectional studies measure and compare people of different ages. Longitudinal studies measure the same people several times at different points in life. Studies using these two methods reveal that proximity to death is a stronger predictor of cognitive decline than age.

Challenges in Cognitive Development in Adulthood

Another common stereotype of later adulthood is that a person becomes senile as they age. Many people live well into their nineties with relatively clear minds. Older adults begin to notice or exhibit signs of neurocognitive disorders in later life (formally, senile dementia).

Common causes of neurocognitive disorders include Parkinson's disease, Creutzfeldt-Jakob disease, and Huntington's disease. They can also be caused by strokes and high blood pressure. As neurocognitive disorders progress, a person experiences disorientation, issues with language, and feelings of frustration. Adults with neurocognitive disorders often feel distressed due to mental confusion, and they can develop depression, anxiety, and psychotic symptoms.

Fig. 1 Cognitive decline, freepik.com

Alzheimer’s Disease

Alzheimer's disease accounts for approximately two-thirds of all neurocognitive disorder cases. People with Alzheimer's first experience a decline in memory followed by a decline in reasoning. Other common signs include unstable walking and a reduced sense of smell. The disease can run its course in as little as five years, or as many as 20 years. In the end, the person may be emotionally flat, disoriented, and mentally vacant.

The brains of Alzheimer's patients begin to lose cells, and the neurons that produce acetylcholine (a neurotransmitter responsible for memory) begin to deteriorate. With more people living longer, finding treatments or a cure for neurocognitive disorders such as Alzheimer's is incredibly important. Some researchers are trying to develop drugs that reduce the activity of GABA, a neurotransmitter that inhibits memory, as one treatment.

Factors Affecting Cognitive Development in Adulthood

Several factors can affect cognitive development in adulthood, including genetics and lifestyle choices. Gene-environment interactions can still play a role as well.

Genetics

As with most things, genetics play a large role in cognitive development in adulthood. As mentioned earlier, people are living longer than ever and a lot of research is geared toward better understanding of neurocognitive disorders. There are specific genes that increase the risk of developing frontotemporal dementia, late-onset Alzheimer's, and early-onset Alzheimer's.

The presence of these genes does not guarantee that you will develop these disorders. How those genes interact with your environment, your life choices, and your life circumstances are also important.

You do not have to possess the gene or gene mutation to develop these neurocognitive disorders. For early-onset Alzheimer's, however, the presence of three gene mutations is a strong indicator that a person is at high risk of developing the disease.

Lifestyle

Several lifestyle choices can affect cognitive development in adulthood. Adults who are more mentally and physically active may be somewhat less likely to develop Alzheimer's. These activities include reading, running, attending lectures, or swimming. Brain plasticity remains throughout life, which means that our brain still holds the ability to improve and change in late adulthood.

Fig. 2 Physical activity, freepik.com

Another lifestyle factor that can affect cognitive development is drug and alcohol use. Smoking, for example, doubles the risk of neurocognitive disorders.