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Why does not enduring episodic memory begin until the
age of three or four?
Theory 1: Repression
Freud thought that forgetting is essential to getting safely through the Oedipal years with their
violent and incestuous impulses. In Freud’s theory, childhood amnesia results from repression of
these impulses, and he thought memories from these years can be retrieved in psychoanalysis by
the use of methods such as free association and dream analysis. There is some evidence that people
tend to have a cluster of childhood memories from about the time Freud thought the Oedipus
complex is resolved. However, like many aspects of Freud’s Theory, his ideas about childhood
amnesia cannot be confirmed or rejected by research.
Theory 2: Brain Immaturity
Another theory points to the immaturity of brain structures. Animal studies have shown that
animals that have mature brains at birth, such as guinea pigs, are able to store permanent memories
early in life, and that animals, such as rats, that are born with immature brains cannot. The brains
of children are immature at birth. They do not have the synaptic connections of a mature brain. A
problem with this theory is, again, why does amnesia affect only autobiographical or episodic
memory?
Theory 3: Limited “M-Space”
One theory that uses the idea of immaturity of brain structures was proposed by a French
psychiatrist, Juan Pascual-Leone, who worked with Piaget and suggested that childhood amnesia
occurs because of limited M-space capacity. M-space is described as “attentional capacity” and
seems to be similar to the concept of short-term memory. Whereas adults can retain approximately
seven chunks in the M-space, small children can retain only one. For this reason, they are unable to
store retrieval cues. They cannot use what they already know to establish retrieval cues because
there is no room in M-space to bring material from long-term memory. Research shows that the
capacity of short-term memory is small in early childhood and increases to adult capacity by
puberty. However, this theory does not account for children’s ability to comprehend and produce
speech. For example, if a child’s attentional capacity is so small, how can the child comprehend a
sentence of seven or eight words?
Theory 4: Schema Differences
Explanations also emphasize the difference between the schemas of small children and those of
adults. Children’s schemas tend to be idiosyncratic. For example, a small child’s “daddy” schema
may include all adult males, football games on TV, daddy’s favorite chair, and the lawn mower.
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Processes like Piaget’s assimilation and accommodation proceed to alter these schemas as the
child’s organization of reality comes to be more like that of the adults of his or her society. Memories
of early childhood may be altered and revised until they are adult memories rather than actually
early childhood memories. The early memories are altered to “fit” into schemas that the child
develops with age. This theory is similar to interference in that as the child matures, new memories
interfere with or replace older memories. This theory seems reasonably credible because it can be
applied to both episodic and semantic memories. Children do not remember the
overgeneralizations they made of words or the restricted context in which they used early
vocabulary. They also do not remember the grammatical structures they used as they began to
combine words into sentences.
Theory 5: Schema Differences, Too
Yet another explanation that emphasizes schemas also points to the difference between the
schemas of early childhood and those of later years. Early memories would have to be represented
by actions, images, and feelings, rather than by symbols, primarily words. Even after children begin
to use words, some psychologists claim that language is used for expressive purpose and
communication, but not as a tool for thought. A child might be four or five years old before
memories begin to be symbolically stored with language. As language takes over as the primary
vehicle for the organization of reality, the ability to retrieve autobiographical memories stored as
emotions, actions, or images is lost because there are not retrieval cues. Aspects of this theory have
appeal, particularly because it specifically considers the child’s lack of language.
The three primary theories of adult forgetting are motivated forgetting or repression, interference,
and cue-dependent memory. Versions of these same theories can be used to explain childhood
amnesia, along with theories that emphasize immaturity of brain structures. The bottom line is that
childhood amnesia remains a mystery. At present, we can only speculate why it occurs.
The Zeigarnik Effect
At about the same time that Freud was talking about motives to repress negative information, Kurt
Lewin and his students were looking at the effects of task motives on memory. Legend has it that
they were puzzled by an occurrence in a Berlin beer garden. In Germany, it is the custom for waiters
to write down what customers ordered after they have eaten and immediately before paying their
bill. Once, however, after the meal had been served and the party had been given their bill, someone
asked the waiter a simple question about their order. It turned out that the waiter could remember
very little of it once he had completed his task.
The result of this observation was a classic experiment that demonstrated greater recall of tasks
before completion than of comparable tasks after completion. This effect of enhanced recall for
uncompleted tasks was named the Zeigarnik Effect after Bluma Zeigarnik, the researcher who
carried out the study.
In the experiment, the participants performed simple tasks that they would be able to accomplish if
given enough time, such as writing down a favorite quotation from memory, solving a riddle, and
doing mental arithmetic problems. In some of the tasks, the participants were interrupted before
they had a chance to carry out the instructions in full. In others, they were allowed to finish. Despite
the fact that the participants spent more time on the completed tasks than on the interrupted ones,
they tended to recall the unfinished tasks better than the finished ones when they were questioned
a few hours later. This superiority of recall for the uncompleted tasks disappeared, however, within
24 hours. Apparently, it was attributable to short-term motivational factors that affected the
rehearsal process.
It might appear that the Zeigarnik effect is inconsistent with the notion of repression, since one
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might expect that people would repress their memory of things left unfinished, particularly if the
lack of completion was viewed as a failure. Later research has suggested a resolution of this
inconsistency by showing that the Zeigamik effect only holds for tasks performed under
nonstressful conditions. When noncompletion is ego involving and threatens the individual’s self-
esteem, there is a tendency for the Zeigamik effect to be reversed, for completed tasks to be
remembered better than uncompleted ones.
Remembering and Forgetting
Why do we forget?