The Making of the Mind: The Neuroscience of Human Nature (16 page)

Talking to ourselves aloud in early childhood is thus a transitional phase to the inner voice that accompanies us every waking moment for the remainder of our days. Perhaps egocentric speech is the fossilized remains of the speech capacity of early human beings when it first turned inward to the self rather than outward to others. Egocentric speech may be a reminder of how the ancestral human mind coopted speech as means of social communication and turned it inward as a medium of pure thought and a part of the interpreter.

Prior to the invention and adoption of language, was it possible that the causal inferences were made and a narrative constructed through mimetic images? Could the interpreter have once existed in the mimetic culture of
Homo erectus
without language? An affirmative answer is just speculation, but cognitive psychology can draw a distinction between the capacity for narrative thought and language. Narrative is a way of describing events that causally link together into a coherent whole—a story. Although narratives are often told using language, a story can also be portrayed with visual-spatial images.
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Imagine, for example, a silent film. Or, an even simpler example is a cartoon,
one without any of the characters saying anything in the little bubbles above their heads. Our dreams provide another example of the capacity for narrative thought in the absence of language. Although dreams can contain dialogue, language is not necessary for dreaming—the imagery by itself is sufficient and stands on its own as a story, albeit often a chaotic, incoherent one. Of course, mime is a prime way of telling a story without language. It is, therefore, conceivable that mimetic images combined with the ability to make causal inferences provided for a prelinguistic version of the brain's interpreter.

Nevertheless, the interpreter of the modern mind makes heavy use of narrative as expressed in language. Although the social benefits of language as a means for communicating with other human beings are unquestionable, the private, interiorized language of the interpreter is just as important to human nature. Subvocalized speech provides running commentary on the panoply of perceptions, memories, and fantasies that stream through consciousness. If we think of the ongoing conscious activity of wakeful cerebral hemispheres as a basketball game, then the interpreter is the voice of the play-by-play commentator.

Everyday thinking and daydreaming reveals a persistent inner voice, as shown in studies that interrupt daily activities with a beeper, followed by a self-report of the contents of consciousness. These reports indicate that about four distinct thoughts pass through awareness in working memory per minute, implying approximately four thousand distinct thoughts during the sixteen hours or so we are awake each day.
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Self-talk accompanies these thoughts about 75 percent of the time; in 25 percent of the cases, the inner voice utters only a few words, but in the remaining 50 percent the internal chatter involves reasonable complete statements and running narratives. Eric Klinger illustrated the kinds of chatter reported by his participants as follows:

The single most common feature of daydreams and other thoughts is self-talk. We hear an unexpected sound and say to ourselves, “What the heck was that?” We walk along appreciating the nice weather, and comment to ourselves, “What a nice day!” We play through our minds an image of a friend. We see him in our daydreams smiling and talking and we think in nearly so many words, “I wonder if he'll visit. I wonder if he really cares about me.”
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Self-talk allows the mind to reflect upon its own experiences. It does so using all the sophistication of language to refer to a complex concept with merely a name. Through the syntax of language, one thought can become subordinated to another and long chains of thoughts can be concatenated. The inner voice makes possible complex patterns of thought that benefit human reasoning, problem solving, decision making, and the capacity to regulate our emotions and behavior. Language may have evolved as a biological adaptation. Improved communication among people allowed for greater cooperation and social cohesion of the group, which has clear advantages for reproduction and survival. But language turned inward in the form of the inner voice might well have been an
exaptation
, the term used by biologists to describe an adaptation that is coopted for a new use. Perhaps once language was established for communicating with one another we found the usefulness of self-talk.

The inner voice of the interpreter benefits from the sound-based form of verbal working memory. This store allows one to maintain thoughts in conscious awareness as the sounds of language, or at least a fragmented version of language. The words of inner speech are held in mind long enough for their meaning and syntactic structure to be grasped, providing a way for thought to gain coherence over time, just as it does in comprehending the outer speech of another person. Thinking in words and the running commentary of the interpreter would be impossible without the transient holding device of verbal working memory.

The inner voice of the interpreter can also be recycled in what can seem like an endless loop, as when a song's lyrics gets stuck in your head or when a voice from the past keeps intruding on an unwanted conversation. For example, think back to your own recent experience of an emotionally charged social exchange with someone close or with an antagonist at school or at work. How many times must a conversation be replayed in our heads before we arrive at an interpretation of why he said what he did last week or why she did what she did yesterday evening?

Our relationships with other people are often managed by attributing causes to our social experiences, and these causal inferences are often made on the basis of rehashed conversations. At the same time, the verbal store can be a vehicle for reworking these conversations (i.e., “If only I had said this when
he said that,” he thought). Past verbalizations can be reimagined just like past visual-spatial events. Working memory can even keep active in consciousness the causal inferences reached by the interpreter (“I can't believe how mean he is to have said that!”). The interpreter can thus ruminate about its own interpretations. All are grist for the interpreter's incessant milling of our conscious experience.

In sum, the interpreter of conscious experience is a left-brain mechanism that ingeniously combines the weighty powers of language and causal inference. Although each part is valuable, in concert they exceed the sum of the parts. The interpreter further draws upon long-term memory to provide a running commentary on consciousness. Working memory can prolong a perception, giving us time to make an interpretation. It can also prolong the interpretation itself as the mind ruminates and stews.

THE SELF AND THE INTERPRETER

Of the tens of thousands of concepts populating a human mind, one stands out as most critical for the entire enterprise. The self-concept is central in regulating our emotions, perceiving the actions of other people, and other cognitive functions. Psychologists theorize that the self is the
sine qua non
organizing structure of the mind. The storage of new events in long-term memory is facilitated by relating the event to the concept of one's self, for example.

The self-concept is a multidimensional entity that changes over time.
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For example, personal identity includes the characteristics of our physical and psychological makeup, but also externally oriented roles that we play in social settings and our social status. It is formed in part by inspection of our own actions, but it is embellished, too, on the basis of what we learn from other people about ourselves. Social comparison to others provides a lens through which the interpreter can make inferences about the self. From very early ages, children compare themselves with others in terms of their height, their skill, their aggression, their friendliness, and so on. The interpreter takes in these social perceptions of how one stacks up relative to others and uses them to reach conclusions—for good or for ill—about the self.

That the self-concept is tightly knitted with the interpreter of the left hemisphere can be demonstrated through split-brain research.
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The split-brain patient named J. W. was shown a set of nine faces. One of the nine was an image of his face. Another was an image of Michael Gazzaniga (M. G.). The remaining seven faces were computer-generated images that began looking very similar to J. W., but then gradually morphed into looking similar to M. G. Each step represented a 10 percent change in facial characteristics away from J. W. and toward M. G. The question is whether the left hemisphere would differ from the right hemisphere in its identification of the images as representing the self. If self-recognition is specially supported by the interpretive system of the left hemisphere, then seeing only 60 percent, or 50 percent, or maybe even less of the self in the image could prompt self-recognition. The results were startling. When the faces were shown to the left hemisphere of J. W., he recognized himself when the image contained only 40 percent of his own features. For presentations to the right hemisphere, it required twice as much relevant information—80 percent of his features—to reach self-recognition. In other words, the left hemisphere was far more likely to infer that the picture was a self-image.

The development of the self-concept does not emerge in a clearly recognizable form until between the ages of eighteen and twenty-four months.
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A child of this age grasps the difference between self and other. This is a crucial development in the growth of the self-concept and the accumulation of a self-history. There must be an “I” and “me” to which events can be attached in long-term memory. Once the self is established, the young child can begin to accumulate new experiences over time, each becoming a fresh entry in the child's autobiography—a mental book of memory of and for the self.

Once the self-concept emerges, it begins its role as the central organizing cognitive structure. Prior to that time, memories are unstable and readily washed over by the daily waves of new experiences. Autobiographical recollections usually only begin around the ages of three or four years and never before the self-concept is established at twenty-four months.
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The loss of very early memories during the first two years of life is known as infantile amnesia. Sigmund Freud famously attributed it to the repression of unpleasant, anxiety-provoking memories. Today, cognitive psychologists see it as an inevitable
consequence of a mind not yet formed, a mind lacking the central organizing structure of a stable self-concept.

The self can change over time in some facets while remaining constant in others. The current contents of working memory at any given point in time provide the raw material for the interpreter to make attributions about the self. If some aspect of one's behavior is especially salient at the moment—such as avoiding interaction with others or feeling in a bad mood—then the left-hemisphere interpreter concludes that the self is shy or depressed, as the case may be. But such thoughts and feelings eventually fade from working memory—they always do, no matter how salient they may seem at the moment. The interpreter, presented with new evidence of the self as seeking social interaction or feeling elated, then concludes that the self is extroverted and happy. Thus, the self-concept changes shape over time as the interpreter accounts for the latest news to enter working memory. Although observing one's own behavior can be a source of inferences about the self, our internal thoughts, emotions, and motivations are especially salient.
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Perhaps our actions are more likely to unfold mindlessly and so are less accessible to the interpreter. By contrast, our thoughts and feelings are by definition active in working memory and readily accessible for reflection and interference by the interpreter.

ILLUSORY INTERPRETATIONS

The brain's interpreter, the cognitive system that assigns the causes behind events and explains, moment to moment, an individual's experiences, has an interesting bias. In a normally functioning brain, thus excluding cases of severe psychopathology such as depression, the interpreter doggedly maintains a positive image of the self, as if it were viewing the world through rose-tinted glasses. In her book
Positive Illusions
, Shelley Taylor documented how people tend to regard themselves, the events of the world around them, and the events fading into the past as well as imagined in the future as more positive than the facts warrant. Normal human thought is, in a sense, taking place in a hall of distorting mirrors. The interpreter sees not reality, but reflected images that make us look better than we really are and that bolster our self-esteem.

In constructing a historical account of some episode in one's personal past, the interpreter slants explanations in the direction of self-enhancement. The self takes on the central and important role in the positive things that transpired and others receive the blame for the negatives. Take, for example, a married couple recollecting an event that led to a fight between them. The wife will recall what transpired quite differently than will the husband—both will invent a personal history that is more self-justifying than an unbiased third observer might relate. Recollections of the past, as with perceptions of the present, are filtered through positive illusions of self-enhancement.

Young children are especially prone to positive illusions about the self. Shelley Taylor captures the essence of youthful self-aggrandizement in the following passage:

Before the exigencies of the world impinge upon the child's self-concept, the child is his or her own hero. With few exceptions, most children think very well of themselves. They believe they are capable at many tasks and abilities, including those they have never tried. They see themselves as popular. Most kindergarteners and first graders say they are at or near the top of the class. They have great expectations for future success. Moreover, these grandiose assessments are quite unresponsive to negative feedback, at least until approximately age seven. Children see themselves as successful on most tasks, even ones on which they have failed.
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