292 ChaPteR 8 Memory
of the week it was, and whether anything of
great importance happened on that date. Mention
November 7, 1991, to Williams, and he says (cor-
rectly), “Let’s see; that would be around when
Magic Johnson announced he had HIV. Yes,
a Thursday. There was a big snowstorm here
the week before.” Neither Williams nor Price
uses mnemonics or can say where their accurate
memories come from. Although Williams and his
family regard his abilities as a source of amuse-
ment, Price describes her nonstop recollections
as a mixed blessing (Parker, Cahill, & McGaugh,
2006). The phenomenon of constant, uncontrol-
lable recall, she wrote, is “totally exhausting. Some
have called it a gift, but I call it a burden. I run my
entire life through my head every day and it drives
me crazy!!!”
Watch the Video The Big Picture: The Woman
Who Cannot Forget at MyPsychLabParadoxically, then, forgetting is adaptive: We
need to forget some things if we wish to remem-
ber efficiently. Piling up facts without distinguish-
ing the important from the trivial is just confus-
ing. Nonetheless, most of us forget more than we
want to and would like to know why.
In the early days of psychology, in an ef-
fort to measure pure memory loss independent
of personal experience, Hermann Ebbinghaus
(1885/1913) memorized long lists of nonsense syl-
lables, such as bok, waf, or ged, and then tested his
retention over a period of several weeks. Most of
his forgetting occurred soon after the initial learn-
ing and then leveled off. Generations of psycholo-
gists adopted Ebbinghaus’s method of studying
memory, but it did not tell them much about the
kinds of memories that people care about most.
A century later, Marigold Linton decided to
find out how people forget real events rather than
nonsense syllables. Like Ebbinghaus, she used
herself as a subject, but she charted the curve of
forgetting over years rather than days. Every day
for 12 years, she recorded on a 4- × 6-inch card
two or more things that had happened to her that
day. Eventually, she accumulated a catalogue of
thousands of discrete events, both trivial (“I have
dinner at the Canton Kitchen: delicious lobster
dish”) and significant (“I land at Orly Airport in
Paris”). Once a month, she took a random sam-
pling of all the cards accumulated to that point,
noted whether she could remember the events on
them, and tried to date the events. Linton (1978)
expected the kind of rapid forgetting reported by
Ebbinghaus. Instead, she found that long-term
forgetting was slower and proceeded at a more
constant pace, as details gradually dropped out of
her memories.Of course, some memories, especially those that
mark important transitions, are more memorable
than others. But why did Linton, like the rest of us,
forget so many details? Psychologists have proposed
five mechanisms to account for forgetting: decay,
replacement of old memories by new ones, interfer-
ence, cue-dependent forgetting, and repression.Decay LO 8.18
One commonsense view, the decay theory, holds
that memories simply fade with time if they are
not accessed now and then. We have already seen
that decay occurs in sensory memory and that
it occurs in short-term memory as well unless
we keep rehearsing the material. However, the
mere passage of time does not account so well for
forgetting in long-term memory. People com-
monly forget things that happened only yester-
day while remembering events from many years
ago. Indeed, some memories, both procedural
and declarative, can last a lifetime. If you learned
to swim as a child, you will still know how to
swim at age 30, even if you have not been in a
pool or lake for 22 years. We are also happy to
report that some school lessons have great stay-
ing power. In one study, people did well on a
Spanish test some 50 years after taking Spanish
in high school, even though most had hardlydecay theory The theory
that information in mem-
ory eventually disappears
if it is not accessed; it
applies better to short-
term than to long-term
memory.
Motor skills, which are stored as procedural memories,
can last a lifetime; they rarely decay.