Placentation Research - Meng Hu's Blog

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IQ AND AGING
are the mean education-adjusted standard scores for selected age
groups to illustrate these results:
Age Group Reading Math Writing
22–25 102 107 104
46–55 102 102 98
81–90 97 93 91
However, further analysis showed that when the two parts of the
reading test were evaluated separately, there was no age-related
decline in mean scores on word reading (which measures acquired
knowledge, akin to Gc), but there was a significant decline
in reading comprehension (which requires Gf to understand the
passages). In addition, when Gf was controlled, the entire agerelated
decrease in mean scores disappeared for math and writing
(Kaufman et al., 2008). In other words, the decline in problemsolving
ability and reasoning with old age also seems to affect our
ability to understand what we read, how well we apply math to
real-life problems, and how well we express our ideas in writing.
The degree to which a task requires Gf also comes back to
haunt our long-term memory. The KAIT has two delayed recall
tasks, both of which assess how well people remember things
they learned about 30–45 minutes earlier in the testing session.
One task requires individuals to remember the words and verbal
concepts that were paired with symbols; the other measures their
recall of facts from news stories that were “broadcast” to them by
a mock newscaster. The first task requires recall of associations
taught by the examiner during the Rebus Learning subtest. That
subtest—illustrated in Figure 3.5—is on the KAIT Gf scale. The
second delayed recall task demands recall of news stories heard
earlier during the Auditory Comprehension subtest, which is on
the KAIT Gc scale. Both delayed recall tasks (measures of longterm
retrieval or Glr) are administered in exactly the same way:
The examiner asks the individual, without advance warning, to
remember information that was taught to her a bit earlier. When
the education-adjusted mean standard scores are examined for an