Chapter 21: Adulthood: Cognitive Development
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The way psychologists conceptualize intelligence has changed
considerably in recent years. Chapter 21 begins by examining
the multidirectional nature of intelligence, noting that some
abilities (such as short-term memory) decline with age, while
others (such as vocabulary) increase with age. This section
includes a discussion of the debate over whether cognitive
abilities inevitably decline during adulthood, or may possibly
remain stable or even increase.
The chapter then examines the contemporary view of
intelligence, which emphasizes its multidimensional nature.
Most experts now believe that there are several distinct
intelligences rather than a single general entity.
The next section of the chapter discusses the cognitive
expertise that often comes with experience, pointing out the
ways in which expert thinking differs from that of the novice.
Expert thinking is more specialized, flexible, and intuitive, and
is guided by more and better problem-solving strategies. The
chapter concludes with a brief discussion of the recent shift in
society in which family skills have become more highly valued
when performed by both women and men.
Chapter Guide
I. What Is Intelligence?
1. Historically, psychologists considered intelligence to be a
single ability, what Charles Spearman referred to as g, or
general intelligence.
2. For the first half of the twentieth century, researchers
believed that intellectual ability rises in childhood, peaks
during adolescence, then declines steadily as age advances.
This belief was based on the results of cross-sectional
research.
3. More recently, researchers have begun to doubt whether
there is an inevitable decline in cognitive functioning with
age. The longitudinal studies of Nancy Bayley and Melita
Oden, for example, indicate that the IQ scores of Terman’s
gifted individuals increased between ages 20 and 50. A
follow-up study by Bayley found that the typical person at
age 36 had improved on tests of vocabulary, comprehension,
and information.
4. The earlier evidence of a decline in cognitive ability may be
attributable to the shortcomings of cross-sectional research.
Because it is impossible to match people in every aspect
except age, cohort effects are inevitable. Longitudinal
research also has shortcomings. People’s performance on
tests might improve with practice. Also, some people leave
the study; those who remain are usually the most stable,
well-functioning adults.
5. Throughout the world, studies have shown a general trend
toward increasing average IQ over successive generations.
This trend is called the Flynn effect.
6. To correct for the limitations of the cross-sectional and
longitudinal research methodologies, K. Warner Schaie
developed the cross-sequential research design for his
Seattle Longitudinal Study. Each time his original cross
section of adults was retested on primary mental abilities
(longitudinal design), he also tested a new group of adults at
each age interval and then followed them longitudinally as
well, thus controlling for the possible effects of retesting, as
well as uncovering the impact of cohort differences. Schaie’s
results confirmed and extended what others had
found: People improve in most mental abilities in
adulthood.
7. In testing older Germans, Paul Baltes found that not until the
80s does every cognitive ability show age-related average
declines.
II. Components of Intelligence: Many and Varied
1. In the 1960s, Raymond Cattell and John Horn differentiated
fluid intelligence and crystallized intelligence.
a. Fluid intelligence is flexible reasoning and is made up of
the basic mental abilities such as inductive reasoning,
abstract thinking, and speed of thinking required for
understanding any subject.
b. Crystallized intelligence refers to the accumulation of
facts, information, and knowledge that comes with
education and experience.
2. Fluid intelligence declines during adulthood, although this
decline is temporarily masked by an increase in crystallized
intelligence.
3. Robert Sternberg has proposed that intelligence is composed
of three distinct parts: an analytic, or academic, aspect
consisting of mental processes that foster efficient learning,
remembering, and thinking; a creative aspect involving the
capacity to be flexible and innovative when dealing with
new situations; and a practical aspect that enables the person
to adapt his or her abilities to contextual demands.
4. Practical intelligence, sometimes called tacit intelligence, is
particularly useful in adulthood, when the demands of daily
life are omnipresent. Interestingly, practical intelligence is
unrelated to traditional intelligence as measured by IQ tests.
5. Which kind of intelligence is most valued depends on events
in each person’s life, partly because of culture and cohort,
and partly because of age.
III. Selective Gains and Losses
1. A hallmark of successful aging is the ability to strategically
use one’s intellectual strengths to compensate for the
declining capacities associated with age. Paul and Margaret
Baltes call this selective optimization with compensation.
2. Some researchers believe that as we age, our intelligence
increases in specific areas that are of importance to us; that
is, each of us becomes a selective expert in a particular area.
3. Research suggests that four features distinguish the expert
from the novice.
a. Experts tend to rely more on their accumulated
experience than on rules to guide them and are thus more
intuitive and less stereotyped in their performance.
b. Many elements of expert performance are automatic.
c. The expert has more, and better, strategies for
accomplishing a particular task.
d. Experts are more flexible in their work.
4. In developing their abilities, experts point to the importance
of practice, usually 10 years or more and several hours a day
before full potential is achieved.
5. Research studies also indicate that expertise is quite specific,
and that practice and specialization cannot always overcome
the effects of age.
6. Historically, research on expertise has focused on
occupations that once had more male than female workers.
Today, more women are working in occupations
traditionally reserved for men. In addition, domestic and
caregiving tasks that were once considered women’s work
have gained new respect and are considered important when
performed by both women and men.