Inner speech

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conscious waking life is made up of silent verbal thinking (Heavey & Hurlburt, 2008). In one study. (Winsler et al., 2006), 96% of all adult participants indicated ...
Inner speech: A neglected phenomenon Alain MORIN Mount Royal College Inner speech arguably plays a central role in human consciousness, and yet, compared to other key psychological phenomena it seems to be somewhat neglected. Two studies were conducted to test the hypothesis that inner speech may be under-cited in the literature and might not have received its share of attention as a research area. Study 1 investigated how frequently inner speech and related terms were mentioned in Introductory Psychology textbooks. Only 7 out of 32 textbooks (21.8%) cited either inner speech, self-talk, private speech, or self-statements in their subject indexes. Study 2 compared citation frequency in PsycINFO for inner speech and related terms to 103 key psychological concepts and phenomena in peer-reviewed journal articles. The average citation frequency for all psychological terms was 1719; by comparison, inner speech was cited 52 times. 84.5% of all terms were cited more often than inner speech. Taken together these observations suggest that inner speech does tend to be overlooked, not so much because it is unimportant but probably because it is taken for granted.

There is no doubt that inner speech represents a central process involved in the dialogical self. Self-narratives most certainly heavily depend on one’s ability to generate speech-for-self (e.g., Fogel et al., 2002; Lysaker & Hermans, 2007), and typical expressions found in the Narrative Psychology literature, such as “person as a storyteller” and “voicing the self”, at least implicitly imply the use of self-talk. As Wiley (2006) points out, American pragmatists like Peirce, James, Mead, Blumer, and Dewey formulated theories that are fundamentally about the dialogical self; all gravitate around the notion of inner speech. Inner speech constitutes a phenomenon not only essential to the dialogical self, but to consciousness and psychology as well. People report that approximately one fourth of their conscious waking life is made up of silent verbal thinking (Heavey & Hurlburt, 2008). In one study (Winsler et al., 2006), 96% of all adult participants indicated that they sometimes talk to themselves aloud when alone. Self-directed speech (first as private speech in children and then as inner speech in adults) has been shown to play a primary role in the regulation of thought and behavior (Fernyhough & Fradley, 2005; Fuson, 1979; Vygotsky, 1943/1962). All features of normal language functions (e.g., reading, writing, speaking, calculating) entail intact inner speech; consequently, loss of inner speech caused by brain damage leads to aphasia, agraphia, alexia, and acalculia (Levine & al., 1982). Verbal short-term memory engages a “phonological loop” (Baddeley & Hitch, 1974) that basically constitutes inner speech; autobiographical memory also involves inner speech, as recent research indicates that personal episodes are often encoded and retrieved in words (Larsen & al., 2002). Self-talk also plays a role in task switching performance (Miyake et al., 2004), remembering the goals of action (Meacham, 1979), and selfawareness (Morin & Michaud, 2007; Steels, 2003). When distorted, inner speech is frequently implicated in various forms of psychological disorders such as schizophrenia, social anxiety, and depression (e.g., Allen et al., 2007; Beazley et al., 2001). Given the central role inner speech obviously plays in human cognition, memory, and consciousness, one would expect frequent reference to it in the scientific literature, as well as rich coverage in general textbooks and specialized handbooks and encyclopedias. Remarkably this does not seem to be the case. As Kinsbourne notes (2000, p. 120), “… inner speech is neglected at Millenium’s end, not even mentioned in the Handbook of Neurolinguistics (1998).” Indeed this statement also applies to the Handbook of Self and Identity (2003) and the Blackwell Companion to Consciousness (2007). I present below two studies conducted to expand on Kinsbourne’s observation that inner speech seems to be a neglected phenomenon. Study 1 investigated the extent to which inner speech and related terms were listed in subject indexes of Introductory Psychology textbooks. Study 2 calculated the number of peer-reviewed journal articles that cited inner speech and related terms in their title between 1900 and 2009; this number was taken as an exploratory objective measure of research output which was then compared to the number of citations for other key psychological concepts and phenomena. Study 1 thus attempted to examine the possibility that inner speech is under-cited in the Introductory Psychology literature,

2 whereas Study 2 explored the notion that as a research area inner speech might not have received its share of attention. Study 1 Method The main purpose of Study 1 was to investigate the frequency with which inner speech was mentioned in Introductory Psychology textbooks. The rationale behind specifically focusing on Introductory Psychology textbooks was as follows. As seen above, inner speech arguably constitutes a key concept in psychology; one would thus expect that it would be introduced to first-year students. Also, inner speech has been studied from various perspectives, most notably cognition, language, development, social cognition, memory, consciousness, and psychotherapy. Each of these perspectives is typically covered as a full chapter in Introductory Psychology textbooks, thus increasing the likelihood that inner speech should be mentioned. The present investigator gathered as many recent textbooks as possible by consulting his private collection, by asking sales and editorial representatives to provide free copies, and by borrowing textbooks from colleagues. A total of 32 Introductory Psychology textbooks were collected and used (see Table 1 in the Results section below). Note that this sampling process was not meant to be exhaustive—an ultimately impossible task to achieve—but merely convenient while unbiased. The next step consisted in scanning through each textbook’s subject index for the term “inner speech” and related words. Many equivalent expressions are used in the literature to refer to the phenomenon of inner speech (Morin, 2009), including “propositional thought”, “subvocal speech”, “covert speech”, “self-referent speech”, “internal dialogue”, “internal monologue”, “auditory imagery”, “subvocalizations”, “subvocal articulation”, “utterances”, “selfverbalizations”, “acommunicative speech”, and “speech-for-self”. However, by far the most commonly used terms for inner speech are “private speech”, “self-talk”, and “self-statements”. Thus, the search was limited to “inner speech” and these three expressions. Results Table 1 presents the textbook analysis performed in Study 1. It contains (1) the author(s) of each textbook, (2) the editor, (3) the year of publication and edition, (4) the title, and (5) the result of the study per se—i.e., were the word “inner speech” and related terms listed in the subject index of the textbook (YES) or not (NO)? Only 7 out of 32 Introductory Psychology textbooks (21.8%) mentioned either inner speech, self-talk, private speech, or self-statements in their subject indexes. Stated differently: 78.2% of all textbooks in the current sample did not make a single reference to inner speech and related terms. Furthermore, closer analysis of those few textbooks that did cite inner speech and other expressions indicated that these mentions were extremely brief. To illustrate, Kosslyn and Rosenberg (2003) and Wade et al. (2007) both only dedicate one paragraph to private speech in their respective chapters on developmental psychology when discussing Vygotsty’s work. Nevid (2003, p. 563) has only one sentence on selftalk in the entire textbook (under psychotherapy), which reads: “In Kevin’s treatment, gradual exposure was combined with calming self-talk, such as telling himself to calm down and relax.” Likewise, Lilienfeld et al.’s analysis (2009, p. 689) of inner speech is summarized as follows: “Therapies modify patients’ self-statements, that is, their ongoing mental dialogue…” It is worth stressing that in this sample, the few textbooks that did cover inner speech did not produce a single in-depth section on the topic that would have provided an historical background and discussion of measurement techniques, development of private speech, neuroanatomy, functions of inner speech, dysfunctional self-talk, connections to consciousness, and so forth. Authors

Editor

Year / Edition

Title

Atkinson et al.

Hartcourt Brace

1996 / 12th

Baron et al.

Allyn & Bacon

Bernstein et al. Bourne & Russo

Houghton Mifflin Norton

1999 / Second Canadian 2003 / 6th 1998 / First

Hilgard’s Introduction to Psychology Psychology Psychology Psychology: Behavior in Context

Inner speech in index? NO NO NO NO

3 Carlson et al.

Pearson

2005 / Third Canadian 1994 / 5th 2006 / Second

The Science of Behavior Psychology Psychological Science

Dworetzky Gazzaniga & Heatherton Gerow Gerrig et al.

West Norton Longman Pearson

Gleitman et al. Huffman Kalat

NO NO

Basic Psychology Psychology and Life

NO NO

Norton Wiley Thomson

1997 / 5th 2009 / First Canadian 2000 / Third 2007 / 8th 2008 / 8th

NO NO NO

Kosslyn & Rosenberg

Allyn & Bacon

2003 / First

Kowalski & Westen Lefton et al.

Wiley Pearson

Lilienfeld et al.

Pearson

2009 / 5th 2008 / Third Canadian 2009 / First

Psychology Psychology in Action Introduction to Psychology Fundamentals of Psychology Psychology Psychology

Lindsay et al.

Thomson

Matlin Morris & Maisto

Hartcourt Brace Prentice Hall

2008 / Third Canadian 1999 / Third 1998 / 10th

Myers Nairne Nevid

Worth Thomson Houghton Mifflin

1998 / 5th 2009 / 5th 2003 / First

Passer et al.

McGraw-Hill

Rathus

Thomson

2008 / Third Canadian 2008 / 9th

Santrock Schacter et al. Sternberg

McGraw-Hill Worth Hartcourt Brace

2000 / 6th 2009 / First 1998 / Second

Wade et al.

Pearson

Weiten & McCann Wood & al. Wortman et al. Zimbardo & Weber

Psychology: From Inquiry to Understanding Psychology: The Adaptive Mind Psychology Psychology: An Introduction Psychology Psychology Psychology: Concepts and Applications Psychology: Frontiers & Applications Psychology: Concepts and Connections Psychology Psychology In Search of the Human Mind Psychology

2007 / Second Canadian Thomson 2007 / First Psychology: Themes Canadian & Variations Pearson 2008 / Fifth The World of Canadian Psychology McGraw-Hill 2000 / First Psychology Canadian Longman 1997 / Second Psychology Table 1. Frequency of mentions to inner speech and related terms in subject indexes of 32 Introductory Psychology textbooks.

NO

YES NO NO YES NO YES YES NO NO YES NO NO NO NO NO YES NO NO NO YES

Study 2 Method The goal of Study 2 was to compare citation frequency for inner speech and related expressions to other key psychological concepts and phenomena in peer-reviewed journal articles. The terms “inner speech”, “private speech”, “self-talk”, and “self-statements” utilized in Study 1 were used again in Study 2. Selection of key terms to which inner speech citation frequency would be contrasted was established by carefully scrutinizing the American Psychological Association (APA)’s Glossary. This list contains 643 key psychological terms with definitions presented in alphabetical order; it is supplied by Gerrig and Zimbardo (2002) and can be found on the organization’s website at www.psychologymatters.org/glossary.html. The glossary is assumed to represent an authoritative and representative directory of the most important concepts in psychology. The list includes an extremely wide array of terms; because the aim here was to compare major psychological processes and phenomena to inner speech related constructs, numerous non-pertinent categories of terms listed in the glossary had to be discarded. These were: effects (e.g., serial position effect), research designs (e.g., A-B-A design),

4 psychology areas (e.g., comparative psychology), brain structures (e.g., hippocampus) and events (e.g., action potential), basic perceptual phenomena (e.g., absolute threshold), medical conditions (e.g., AIDS), mathematical formulas and procedures (e.g., algorithm), general disorders (e.g., psychotic disorders), general coping mechanisms (e.g., anticipatory coping), general theories (e.g., attribution theory), perceptual qualities (e.g., brightness), psychological tests (e.g., Thematic Apperception Test), general principles (e.g., classical conditioning), general terms (e.g., behavior), methodological issues (e.g., confounding variable), and psychotherapeutic techniques (e.g., placebo therapy). To avoid redundancy, specific cases of a more general process or phenomenon were eliminated; to illustrate, “heuristics” was retained while “availability heuristic”, “anchoring heuristic”, “representativeness heuristic”, and “simulation heuristic” were discarded. A final list of 105 words was selected from the original Glossary (see Table 2 in the Results section below). PsycINFO was used as a database to perform the citation search. PsycINFO is maintained by the APA; it contains nearly 2.3 million citations of scholarly journal articles, book chapters, books, and dissertations in psychology dating as far back as the 1800s. Ninety seven percent of the covered material is peer-reviewed and includes international material selected from more than 2100 periodicals in more than 25 languages. An advanced search was conducted for each term listed in Table 2 using the following limits: (1) find term in title; (2) from 1900 to 2009; (3) publication type: peer reviewed journal articles; (4) population group: humans; (5) age groups, intended audience, methodology, document type, book type, and classification codes: all; (6) exclude dissertations. Results Table 2 presents the terms searched in the titles of peer-reviewed journal articles using PsycINFO (left column) and the number of citations obtained in ascending order (right column). The words “conservation” (821 citations) and “resistance” (2115 citations) yielded many results not directly related to Piaget’s theory (for conservation—e.g., wildlife, energy) and Freud’s theory (for resistance—e.g., to insuline or extinction) and were thus discarded. 103 terms were thus retained from the original APA Glossary list. Terms Inner speech Private speech Self-statement Self-talk Elaborative rehearsal Reconstructive memory Behavioral confirmation Diffusion of responsibility Hierarchy of needs Fundamental attribution error Bystander intervention Observer bias Lucid dreaming Controlled processes Group polarization Serial processing Self-serving bias Procedural memory Sensory memory Chunking Object permanence Self-fulfilling prophecy Groupthink Id Catharsis Automatic processes Mnemonics Archetype

N of citations 52 69 80 84 5 17 20 20 25 26 29 29 32 36 37 37 39 45 49 50 55 62 67 68 74 95 99 102

5 Possible self Social categorization Ageism Observational learning Self-handicapping Egocentrism Cognitive map Declarative memory Superego Free association Divergent thinking Metamemory Cognitive dissonance Internalization Heuristics Cognitive appraisal Parenting style Blocking Shyness Sexism Self-actualization Learned helplessness Defense mechanism Self-awareness Semantic memory Long-term memory Altruism Repression Prototype Assimilation Episodic memory Persuasion Conformity Meditation Accommodation Delusion Intimacy Prejudice Schema Countertransference Stigma Unconscious Biofeedback Hallucination Transference Short-term memory Body image Illusion Socialization Inference Ego Encoding Stereotype Compliance Interference Retrieval Working memory Consciousness Self-efficacy priming Self-concept Creativity Imagery Reasoning Problem solving Self-esteem

103 104 105 123 128 139 141 149 165 186 190 190 201 203 205 215 220 237 241 256 333 337 354 364 369 382 409 420 434 463 502 572 613 622 655 818 874 910 913 934 989 1040 1079 1143 1186 1279 1372 1452 1537 1579 1734 1734 1961 2001 2014 2072 2239 2337 2410 2451 2580 2732 2970 3047 3496 3661

6 Attribution 3830 Attachment 3908 Aggression 4189 Acquisition 4299 Decision making 5114 Recall 5133 Intelligence 5758 Judgment 6870 Recognition 7732 Attention 10700 Anxiety 14263 Stress 17423 Attitude 19887 Table 2. Citation frequencies obtained from PsycINFO in peer-reviewed journal articles for (1) inner speech and related terms, and (2) other key psychological concepts and phenomena.

The average citation frequency for all the Glossary terms was 1719; by comparison, the terms “inner speech”, “private speech”, “self-statement”, and “self-talk” were cited 52, 69, 80, and 84 times, respectively. 84.5% of all terms were cited more often than inner speech, 80.6% more often than private speech, and 79.6% more often than both self-talk and self-statement. Sixteen terms were cited less often than inner speech, 20 less often than private speech, and 21 less often than both self-talk and self-statement; 87 terms were cited more often than inner speech, 83 more often than private speech, and 82 more often than both self-talk and selfstatement. Remarkably, imagery, the visual counterpart of inner speech, was cited 2970 times while inner speech was cited 52 times. Figure 1 below compares citation frequencies for 19 terms selected form the list offered in Table 2. These terms were chosen for their high degree of affinity with inner speech in that they may engage or underlie inner speech activity (e.g., short-term memory, self-awareness) and/or are closely related or theoretically comparable to inner speech (e.g., again imagery). Note that inner speech represents the second least frequently cited term (after controlled processes) on the chart.

10,700 7000 6500

5500 5000 4500

Concepts Figure 1. Comparison of PsycINFO citation frequencies for 19 terms selected form the APA Glossary.

Attention

Judgment

Recall

Decision making

Attribution

Problem solving

Reasoning

Imagery

Consciousness

Working memory

0

Retrieval

500

Encoding

1000

Self-awareness

1500

Cognitive appraisal

2000

Internalization

2500

Inner speech

3000

Cognitive dissonance

3500

Short-term memory

4000

Controlled processes

N of citations in PsycINFO

6000

7 Discussion and Conclusion Study 1 strongly suggests that inner speech is under-cited in the Introductory Psychology literature; when it is mentioned, coverage is superficial at best. This constitutes a surprising observation given the central role inner speech plays in consciousness and cognition. Future studies could explore if this inder-citation holds for Introductory Psychology textbooks, Developmental Psychology textbooks, Cognition texbooks, Psychotherapy textbooks, and so forth. The present author has already been conducting informal versions of such studies with Social Cognition textbooks in recent years, which so far have yielded results that are highly consistent with those obtained in Study 1 presented here. Study 2 shows that compared to other important psychological concepts and phenomena, inner speech and related terms are much less frequently cited in peer-reviewed journal articles. Although speculative, one can tentatively argue that the low citation frequencies for inner speech are indicative of relatively poor research output. This is not to say that inner speech has not generated its share of research. To illustrate, Vygotsky’s (1943/1962) original ideas about private speech development stimulated numerous attempts at testing these hypotheses (e.g., Kohlberg et al., 1968); this line of research has recently re-emerged (e.g., Winsler et al., 2000). Sophisticated brain-imaging techniques have motivated the publication of quite a few empirical articles that now largely support the explanation of auditory verbal hallucinations in schizophrenic patients in terms of inner speech monitoring deficits (e.g., Shergill et al. 2003). Morever, dysfunctional self-talk and self-statement modification certainly represent reasonably rich research areas (e.g., Meichenbaum & Goodman, 1971). Yet the fact remains that in Study 2 inner speech and related terms produced much fewer citations in PsychINFO than for many other psychological concepts from the APA Glossary, suggesting that inner speech has been neglected compared to other research areas. Why would inner speech tend to be ignored in the literature and even possibly neglected as a research topic? Although one is inclined to overlook unimportant things, most psychologists would concur that inner speech does represent a central phenomenon and thus would reject the claim that there has been a tendency to ignore it because it is trivial. Rather, one might argue that it is precisely because inner speech is so central to our mental life that we take it for granted—and hence are predisposed to overlook it—a tendency that ultimately manifests itself as under-citation and lack of research biases. 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