Despite the importance of commitment in moral and political philosophy, there has hitherto been little extended analysis of it. Marcel Lieberman examines the conditions under which commitment is possible, and offers at the same time an indirect argument for moral realism. He argues that realist evaluative beliefs are functionally required for commitment - especially regarding its role in self-understanding - and since it is only within a realist framework that such beliefs make sense, realism about values is a condition (...) for the possibility of commitment itself. His ambitious study addresses questions that are of great interest to analytic philosophers but also makes many connections with continental philosophy and with folk psychology, sociology and cognitive science, and will be seen as a distinctive intervention in the debate about moral realism. (shrink)

Despite the importance of commitment in moral and political philosophy, there has hitherto been little extended analysis of it. Marcel Lieberman examines the conditions under which commitment is possible, and offers at the same time an indirect argument for moral realism. He argues that realist evaluative beliefs are functionally required for commitment - especially regarding its role in self-understanding - and since it is only within a realist framework that such beliefs make sense, realism about values is a condition (...) for the possibility of commitment itself. His ambitious study addresses questions that are of great interest to analytic philosophers but also makes many connections with continental philosophy and with folk psychology, sociology and cognitive science, and will be seen as a distinctive intervention in the debate about moral realism. (shrink)

Why was the South African state so much more successful than the Brazilian state in its attempts to collect income taxes during the twentieth century? Nationally distinctive tax policies and patterns of administration can be explained by examining the impact of contrasting definitions of National Political Community, specified in critical constitutions written around the turn of the century. The ways in which racial and spatial cleavages were addressed in the 1891 Brazilian constitution and the 1909 South Africa Act influenced the (...) development of interclass and intraclass relations, which in turn affected the willingness of upper-income groups to accept state demands for income tax payments. Varied patterns of state development were largely predicated on contested notions of “us” and “them.”. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumWhat’s Psychiatry Got to do With It?Paul B. Lieberman, MDIf in life we are surrounded by death, so too in the health of our intellect by madness.—WittgensteinDelirium is a medical syndrome defined as “a relatively acute decline in cognition that fluctuates over hours or days” whose primary manifestation is a deficit of attention. It is common, estimated to occur in 10% to more than 50% of hospitalized (...) patients, with higher prevalence rates among people in nursing homes and at the end of life. It is often fatal, with a mortality rate in the hospital estimated to be 25% to 33%. Caused by a wide variety of conditions and frequently difficult to diagnose, it lacks characteristic postmortem pathology (Josephson & Miller 2018)‘Excited delirium,’ as Byju and Friesen forcefully argue (Byju & Friesen, 2023), is, if nothing else, an excuse. The ‘diagnosis’ has not been empirically validated and remains controversial (American Psychiatric Association, 2020). And while delirium is usually treated by internists and emergency medicine physicians, psychiatrists should also be concerned about the misuse of a putative medical diagnosis and join actively in discussion about it. For one thing, patients mis-diagnosed with this condition, as Byju and Friesen’s examples suggest, may actually have another psychiatric condition and, so, be people for whose safety we should advocate. Moreover, the kinds of police interventions which Byju and Friesen document as involving excited delirium also befall patients with other psychiatric problems in whom the issue of delirium does not arise.There are at least two broad ways in which psychiatrists are qualified and obligated to engage with this issue. As physicians, we should join our medical colleagues in carefully but persistently telling the scientific, medical truth. As psychiatrists, we should bring psychiatric knowledge into the discussion, for example, by explaining what can happen when people who do not, apparently, have a diagnosable mental disorder interact under stress with other people who, apparently, do.Delirium is a clinical diagnosis, made when characteristic signs and symptoms are present which should not be made ‘by exclusion’ when, as may happen, other causes are not found. There is no evidence of delirium in any of the three clinical descriptions Byju and Friesen provide. Perhaps such evidence exists which is not in their brief reports, but these three people appear to have had, either, another psychiatric condition, such as psychosis or drug intoxication, or perhaps no [End Page 353] diagnosis at all. Psychiatrists are particularly wellpositioned to make this point since patients with mental health problems are often misdiagnosed when they seek medical attention and are told, and treated as if, “it’s all (“just”!) psychological.”Excited delirium, if it exists, is fatal in 10% of cases (Gonin, Beysard, Hersin, & Carron, 2018) and, although this is lower than the rate for delirium in general, it is still high. Medical personnel must be available to evaluate and ensure the safety of patients in custody.The potential conflict between protecting the patient and protecting the public should not be overstated. Although physical trauma and excessive administration of medications, including ketamine 500 mg IV (Orhurhu, Vashicht, Claus, & Cohen, 2023) can be lethal, mechanical restraint by itself is not (Chieze et al., 2019; Gleerup et al., 2019): something else is necessary, such as asphyxiation (Evans, Wood, & Lambert, 2003). Nor is restraint necessary in many cases in which ‘de-escalation’ techniques can be equally effective (Garriga et al., 2016; Fernández-Costa, 2020). Perhaps these points are best made by law enforcement leaders—and they have been—but psychiatrists can add that safe management of potential violence can be provided for agitated people with psychiatric conditions.Although it is not clear what kind of strength ‘superhuman’ strength might be (certainly not medical), relative imperviousness to pain is clinically described. Its locus classicus is Beecher’s observation, during World War II, that injured soldiers awaiting return home from the front, required lower than usual doses of analgesics (Beecher, 1946). And it’s a common experience, scientifically confirmed, that physical trauma may not become painful until sometime after the injury (Melzack, Wall, & Ty, 1982). But pain is a warning. Its absence is not a license, but a caution... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Recovering One's Self from PsychosisA Philosophical AnalysisThe author reports no conflicts of interest.Rosanna Wannberg (2024) has given us a dense but helpful introduction to certain philosophical questions raised by the fact that many patients recovering from psychotic illnesses describe their recovery in terms of gaining or regaining a 'sense of self' and a 'sense of agency,' which often involves acceptance of the 'fact' of being mentally ill, for example, (...) of 'having schizophrenia.' She raises two important questions: How should we understand what is going on in these accounts? and What are the implications of these reports for our understanding of what it is to have a 'sense of self' or a 'sense of agency'—of 'subjectivity' generally—which might have, both, clinical and nonclinical implications?What does it mean to have a self or a sense of having one, agency or a sense of having it? One might think these are the possession or experience of something 'inner' such as feelings of confidence or assurance, perhaps having a kind of inner structure or a set of deeply held ideas which give us coherence, motivate us and justify our actions, and which we can know by 'looking inward,' in an introspective act which provides direct, privileged acquaintance.Yet Wittgenstein called this a dangerously misleading 'picture' which 'held us captive,' and needed always to be 'gotten rid of' (Wittgenstein, 1958). One way of seeing the problem is to consider that no inner 'object,' no thing inside us, can be, or give us a sense of having, a self or agency, because no mere thing (whether an experience of confidence, or having an inner structure) can have any meaning or provide any explanation. A thing (like a word on a page) is just a thing—inert, dead— and must be interpreted, that is used, before it can play a role in our 'forms of life' (Wittgenstein, 1958) including explaining our sense of self or agency.Semantic externalists (Burge, 1979; Putnam, 1975), have argued that even what is internal to our minds—like thoughts—have contents which are determined by experiences in the 'outside' world in which we have lived and learned: if our experiences in the world, they have shown, were different, then so, also, would be the contents of our thoughts. It has even been argued that internal mental experiences which appear to be purely phenomenological (such as an image or a thought-token, so-called narrow content) can only [End Page 67] be identified and thought about using concepts having references in the external world: there is, so it is claimed, no narrow content (Yli-Vakkuri and Hawthorne, 2018); or, if there is, it is of no explanatory use in psychology (Fodor, 1994).If this is the philosophical background from which Wannberg confronts first-person accounts of recovery from psychosis which include (re)gaining a sense of self or agency, and if this philosophy is right, what becomes of the accounts? How are they to be understood?To meet this challenge, Wannberg invokes an alternative account of self-possession and firstperson authority provided by Richard Moran (2001). Moran's position is that we find or possess ourselves when we find or hold beliefs about the world which we do not merely believe but endorse or avow, where to endorse or avow a belief about the world is to find and endorse reasons in the world, which support that belief. Thus, I can avow that it's raining if I can look outside and see that it is raining. This Moran calls the transparency condition. Endorsing or avowing both a belief and the external reasons for it gives the self what Moran refers to as authenticity and which also might be said to provide cohesion, consistency and intelligibility—plausibly, a 'sense of self.'The transparency condition also applies to beliefs that justify actions. We act intentionally when we can give good reasons for what we do (Anscombe, 1957; Moran, 2001) and we can give good reasons for what we do when we can identify facts in the world that support those reasons. Thus, the transparency condition can explain both a sense of self and a sense... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Minding Psychiatric PracticePaul B. Lieberman, MD (bio)In recent discussions of what makes or should make something 'a psychiatric disorder' (if anything does; Lange, 2007), attention and contention have mostly involved problems distinguishing disorder from normal life, expectable suffering, neurological disease, criminality, prejudice, error, religious experience and effects of injustice, but the question of what makes or should make something psychiatric is also important and difficult to answer. It's (...) important because general conceptions of what kinds of things we treat (e.g., disorders of the heart, brain, or mind) guide practice by specifying what constitutes, nurtures or poisons them, ways they may break apart or be repaired and processes that produce change, as well as by helping to draw appropriate boundaries between psychiatry and other fields. It's difficult because psychiatry comprises many kinds of objects, theories and forms of practice (primarily biomedical, psychodynamic and cognitive behavioral), and we don't know which, if any, are 'natural' or valid. It's also not established whether or why all or any should be called, 'psychiatric,' what explains their being so-called (if it is correct to do so), or which may be fundamental or constitutive and which derivative and potentially eliminable.One appealing answer (the Diagnostic and Statistical Manual of Mental Disorders [DSM] an swer; American Psychiatric Association, 2013) to the question of what makes something psychiatric is that it is mental in some essential way. But few psychiatrists could explain what that might mean, nor would many be able to say what a mental disorder is or defend the idea that the conditions they work with are (always?) such things (though many probably wouldn't deny it either; they wouldn't know what to say and most wouldn't think it mattered). But if the idea that 'psychiatric disorders are essentially mental' seems obvious yet unclear to psychiatrists, what's the alternative? And if no alternative leaps to mind, then are psychiatrists practicing without knowing what they're treating?In "What makes a disorder 'mental'? A practical treatment of psychiatric disorder," Joseph Gough (2023) addresses these problems with two bold proposals: first, that we abandon altogether using 'mental' (assuming we understand its meaning) in the definition of 'psychiatric disorder,' and, second, that we, instead, define psychiatric disorders as those conditions best treated by psychiatrists (including psychologists, social workers, nurses and other practitioners).To a psychiatrist, these proposals seem, both, a welcome validation of our work ("At last, someone appreciates us!"), but also a troubling destabilization of how we understand that work ("That can't be right: it's backwards!") In Gough's [End Page 37] wide-ranging and carefully reasoned defense of his two proposals, he offers many novel and provocative insights relevant to problems defining psychiatric disorders. I will consider only a few of the issues he raises, which I think are especially worth emphasis and further thought.Gough initially rejects mentality in the definition of psychiatric disorder by reminding us that it is neither sufficient nor necessary for inclusion in the DSM. Vision is mental but blindness is not in the manual; caffeinism and erectile dysfunction are not mental but are included. Later, he offers two additional reasons for abandoning mentality: it promotes stigma and encourages dualism. I think all these arguments are correct. (Although blindness is not the best example because DSM defines mental disorders as disturbances of "thought, feeling and behavior" and blindness is none of these. But many other examples (e.g., encephalopathies) could make the point.)But Gough passes over this issue too quickly: we should pause and consider more carefully possible reasons to keep or even privilege the mental in psychiatry as well as the losses we might suffer if we gave it up. The examples and arguments he offers for abandoning the mental could be contested if one were motivated to do so. For example, one could argue, as Gough does elsewhere, that the DSM is just wrong sometimes and should be revised. Perhaps, as Gough briefly considers, there is a subset of 'mental' disorders that are properly psychiatric (where, e.g., certain favored features such as meaning, agency, narrative, or connection of 'self and world' are preserved, and... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:The Nature of Proof in PsychiatryPaul Lieberman (bio)Keywordspsychotherapy process, knowledge and psychiatry, externalism, WittgensteinThis vivid clinical report illustrates recognizably, and provocatively, a number of routine, but often unexamined, clinical questions. In its few paragraphs, it depicts challenges that each practitioner confronts, and, in the flux of clinical work, addresses, however implicitly and imperfectly, every day: From what data, and by what processes, does a clinical formulation, or way (...) of understanding, come into being? How do we appraise its accuracy and adequacy? Of what value is even a well-substantiated understanding, in the mind of the therapist, to the patient? What is the power of empathy as a treatment tool? How do we assess someone's status as a “good candidate for therapy?” When, typically, only the outlines of a problem are visible, and its origins and implications are largely hidden, by what right do we recommend psychotherapy, and with what conception, at what level of detail, of what its outcome will be? These are among the questions that Dr. Bailey's story challenges us to address.They are clinical questions, of course, because they deal with empirical matters of fact—psychological processes, outcomes studies, and evidence. But they are also philosophical because, as Freud insisted and Dr. Bailey shows, information obtained in the clinical situation often has power and authority that lead us to believe we understand what is going on, understand the other person, even in the absence of scientifically tested hypotheses, or the clear application of research-based evidence. Interactions between people—including clinical interactions—have a life and ability to engage us. Their meanings can seem so transparent and convincing that no doubt or questioning may seem cogent. At their most powerful, such experiences can reawaken us to important realms of experience and feeling which we might, otherwise, forget, ignore, suppress, deny, or in other ways keep out of awareness; they have the potential to arouse us and reconnect us with truths that, once revived, can seem both valid and important—perhaps the kind of experience that we may derive from works of art or literature (in fact, Dr. Bailey's account could be seen as a clinical parable—meant to be neither true nor false, but instructive). But even less dramatic examples are commonplace: we do routinely claim to know and be able to interpret and understand the actions of other people from our everyday interactions with and observations of them.What is less clear is how to account for these convictions and how to appraise their value, because they do not derive from established scientific procedures. Clinical intuition has a role throughout medicine, but we usually expect it to be subjected later to more rigorous tests to establish the correct diagnosis. Yet, as Dr. Bailey's case illustrates, clinical intuition in the psychiatric encounter seems somehow different. When Colin [End Page 225] leads Dr. Bailey to the conclusion that a “painful lack of wounds” has made him depressed, we find this credible. It seems similarly credible that Dr. Bailey might be anxious about his own capacity to defend his young family, because he says he is, that he perceives Colin as testing his manhood or sincerity, because that seems to fit Colin's temperament, that being accurately understood is helpful, because most of us have had that experience and valued it, and that, most generally, an absence of challenge or of activity could be depressing. But suppose a patient believed that a painful lack of wounds produced diabetes instead of depression, or suppose he had developed epilepsy and attributed that to an absence of combat experience. We might see these as ‘pre-scientific’ or ‘hypothesis-generating’ (or worse). By contrast, it seems timid to consider psychiatric formulations to be always and only provisional or hypothetical.In what ways and to what extent should we expect psychiatry to be different, and why? Several considerations suggest that psychiatry's reasons are not, always and everywhere, the same as those of general medicine, nor are its objectives.In general medicine, we distinguish between signs and symptoms, on the one hand, and “underlying” disease processes, on the other. But in psychiatry, this distinction can be... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:The Meanings and Function of Anti-System Ideology in the Weimar RepublicBen LiebermanThere are few, if any, ideological terms in the extensive historiography of the Weimar Republic so omnipresent and yet at the same time so obscure as the word “system.” Historical accounts of the Weimar Republic are strewn with references to the “system.” In recent works on the Weimar Republic Hagen Schulze points to the opposition of bourgeois (bürgerliche) (...) parties to the “Weimar ‘system,’ “ Detlev Peukert notes “hatred of ‘the system,’ the political and social order of the Republic”; Knut Borchardt observes the loss of faith in the capacity of “the system” to satisfy expectations; and Hans Mommsen refers to the “political system,” the “party system” and the “parliamentary system.” 1Historians, whatever their other differences, agree that mounting opposition to the System weakened the Weimar Republic, but the usefulness of this observation requires analysis of the meaning or meanings of the System. What, then, was the Weimar System? Surprisingly, many accounts of the Weimar Republic do not even attempt to provide a definition of the System, and the term receives only cursory treatment in several specialized works on ideology of the Weimar era. 2 Anti-System politics does receive attention, but Thomas [End Page 355] Childers’s insightful and pioneering essay on “anti-system politics” concentrates on mobilization against the System rather than on the problem of defining it. 3The best existing analysis of the System in Kurt Sontheimer’s valuable study of anti-democratic thought in the Weimar Republic suggests that historians cannot take the meaning of the term as a given. Sontheimer establishes that the System formed part of the array of anti-democratic thought of the Weimar Republic, but he also notes that the term’s meaning cannot easily be pinned down. The System conveyed a variety of political and economic meanings and ultimately formed a “nationalist counter myth.” 4During the Weimar Republic, attacks against the System emanated from a wide range of sources, most notably from a variety of nationalists as well as from Communists. Nationalists of many leanings detested the System. The DNVP (German National People’s Party), the largest political party of the right for most of the Weimar Republic, hated the System. So, too, did conservative revolutionaries and völkisch (ethnic or racist nationalist) groups including nationalist associations and the National Socialists. At the other end of the political spectrum, attacks against the System also surfaced in the pronouncements of the KPD (German Communist Party). 5No single ideological line of attack doomed the Weimar Republic, but use by an extraordinarily broad range of political groups lent tremendous force to anti-System discourse. Adopted by foes who sometimes agreed on little else, the System was the targets of repeated attacks spread across the German political spectrum and called into question Weimar legitimacy. Analyzing this broad pattern of use raises several tasks. As a prelude to investigating anti-System terminology, it is necessary to map out the patterns of use of the System during the Weimar Republic. The very ability of rival groups to adopt anti-System suggests that the System incorporated varied meanings.Beyond investigating the meaning or meanings of the System, an analysis of anti-System terminology should also explore the appeal and influence of anti-System terminology. Why did such a broad range of groups adopt anti-System discourse, and how did acceptance of anti-System terminology help to discredit the Weimar Republic and designate alternatives for Germany’s future? [End Page 356]Describing Weimar’s perceived failings, anti-System terminology simultaneously provided a partial guide to a presumably-better Germany without the System. The System came to envelop many institutions of German public life, but attention should also be paid to spaces left unoccupied by the System. What, if any, institutions or structures of public life were left untainted by the broad wave of attacks against the System? If the hated System could be swept away, what would be left in its place? It is noteworthy that the many enemies of the System generally desired a strong state.Exploring the effects of broad attacks against the System, analysis of the System should also... (shrink)

The renowned cognitive scientist Philip Lieberman demonstrates that there is no better guide to the world's living--and still evolving--things than Darwin and that the phenomena he observed are still being explored at the frontiers of science. Lieberman relates the insights that led to groundbreaking discoveries in both Darwin's time and our own.

The article examines Bentham's writings and activities during the period 1788 to 1803, when much of his energy was devoted to the unsuccessful Panopticon prison project. Focusing on the varied strategies pursued by Bentham to secure public notice for his legislative programme, the discussion emphasizes how far in his writings he had moved from the central core of his legislative theory by the first years of the nineteenth century. This perspective, in turn, clarifies the critical importance to Bentham's later career (...) of the successful reception of Etienne Dumont's redaction of the Benthamite legislative science in the 1802 Trait?s de l?gislation. (shrink)

Many animals, including dogs, produce vocal signals in which their mouths open and close producing In contrast, the vocal signals of species other than humans are tied to emotional states. The Broca's-Wernicke's area model of the brain bases of language is wrong.

A comprehensive account of English legal thought in the age of Blackstone and Bentham for nearly a century, The Province of Legislation Determined advances an ambitious reinterpretation of eighteenth-century attitudes to social change and law reform. Professor Lieberman's bold synthesis rests on a wide survey of legal materials and on a detailed discussion of Blackstone's Commentaries, the jurisprudence of Lord Kames and the Scottish Enlightenment, the chief justiceship of Lord Mansfield, the penal theories of Eden and Romilly, and the (...) legislative science of Jeremy Bentham. The study relates legal developments to the broader fabric of eighteenth-century social and political theory, and offers a novel assessment of the character of the common law tradition and of Bentham's contribution to the ideology of reform. (shrink)

Under the normal assumptions of quantum field theory, Haag’s theorem states that any field unitarily equivalent to a free field must itself be a free field. Unfortunately, the derivation of the Dyson series perturbation expansion relies on the use of the interaction picture, in which the interacting field is unitarily equivalent to the free field but must still account for interactions. Thus, the traditional perturbative derivation of the scattering matrix in quantum field theory is mathematically ill defined. Nevertheless, perturbative quantum (...) field theory is currently the only practical approach for addressing scattering for realistic interactions, and it has been spectacularly successful in making empirical predictions. This paper explains this success by showing that Haag’s Theorem can be avoided when quantum field theory is formulated using an invariant, fifth path parameter in addition to the usual four position parameters, such that the Dyson perturbation expansion for the scattering matrix can still be reproduced. As a result, the parameterized formalism provides a consistent foundation for the interpretation of quantum field theory as used in practice and, perhaps, for better dealing with other mathematical issues. (shrink)

I explore Lacan’s theory of the subject by responding to two well-known criticisms of it, found in Borch-Jacobsen’s Lacan and Lacoue-Labarthe and Nancy’s The Title of the Letter. I argue that the relation of the subject to language is an important part of Lacan’s theory, but his conception of the subject cannot be reduced to language, as the critiques allege. The real must be included in the picture too. I then discuss the situation of Lacan’s subject between language and the (...) real, and conclude with a contrast of Lacan’s subversion of the subject to a Derridean paleonymic approach. (shrink)

Due to the intense selection pressure against inbreeding, humans are expected to possess psychological adaptations that regulate mate choice and avoid inbreeding. From a gene’s-eye perspective, there is little difference in the evolutionary costs between situations where an individual him/herself is participating in inbreeding and inbreeding among other close relatives. The difference is merely quantitative, as fitness can be compromised via both routes. The question is whether humans are sensitive to the direct as well as indirect costs of inbreeding. Using (...) responses from a large population-based sample (27,364 responses from 2,353 participants), we found that human motivations to avoid inbreeding closely track the theoretical costs of inbreeding as predicted by inclusive-fitness theory. Participants were asked to select in a forced choice paradigm, which of two acts of inbreeding with actual family members they would want to avoid most. We found that the estimated fitness costs explained 83.6% of participant choices. Importantly, fitness costs explained choices also when the self was not involved. We conclude that humans intuit the indirect fitness costs of mating decisions made by close family members and that psychological inbreeding avoidance mechanisms extend beyond self-regulation. (shrink)

We provide comprehensive, level-by-level characterizations of large cardinals, in the range from weakly compact to strongly compact, by closure properties of powerful images of accessible functors. In the process, we show that these properties are also equivalent to various forms of tameness for abstract elementary classes. This systematizes and extends results of [W. Boney and S. Unger, Large cardinal axioms from tameness in AECs, Proc. Amer. Math. Soc.145(10) (2017) 4517–4532; A. Brooke-Taylor and J. Rosický, Accessible images revisited, Proc. AMS145(3) (2016) (...) 1317–1327; M. Lieberman, A category-theoretic characterization of almost measurable cardinals (Submitted, 2018); M. Lieberman and J. Rosický, Classification theory for accessible categories. J. Symbolic Logic81(1) (2016) 1647–1648]. (shrink)

Research has shown that adults can engage in cognitive offloading, whereby internal processes are offloaded onto the environment to help task performance. Here, we investigate an application of this approach with children, in particular children with poor working memory. Participants were required to remember and recall sequences of colors by placing colored blocks in the correct serial order. In one condition the blocks were arranged to facilitate cognitive offloading (i.e., grouped by color), whereas in the other condition they were arranged (...) randomly. Across two experiments (total N = 166) the ordered condition improved task performance for children with low working memory ability. In addition, participants in Experiment 2 rated the difficulty of the two arrangements and performed a further condition in which they were given an opportunity to freely arrange the blocks before completing the task. Despite performing better in the ordered condition, children with low working memory ability did not rate the ordered arrangement as easier, nor did they choose an ordered arrangement when given the opportunity to do so. This research shows that cognitive offloading can also be a useful process in populations other than typical adults, and the implications of this work for supporting children with poor working memory are discussed. (shrink)

This volume, originally published in 1987, is a collection of seven previously published essays, here slightly modified. Six of these were previously published in various journals over the years 1971-1984 and one was presented at a Kierkegaard conference at St. Olaf college in 1985.

Iconic signs are overrepresented in the vocabularies of young deaf children, but it is unclear why. It is possible that iconic signs are easier for children to learn, but it is also possible that adults use iconic signs in child-directed signing in ways that make them more learnable, either by using them more often than less iconic signs or by lengthening them. We analyzed videos of naturalistic play sessions between parents and deaf children aged 9–60 months. To determine whether iconic (...) signs are overrepresented during child-directed signing, we compared the iconicity of actual parent productions to the iconicity of simulated vocabularies designed to estimate chance levels of iconicity. For almost all dyads, parent sign types and tokens were not more iconic than the simulated vocabularies, suggesting that parents do not select more iconic signs during child-directed signing. To determine whether iconic signs are more likely to be lengthened, we ran a linear regression predicting sign duration, and found an interaction between age and iconicity: while parents of younger children produced non-iconic and iconic signs with similar durations, parents of older children produced non-iconic signs with shorter durations than iconic signs. Thus, parents sign more quickly with older children than younger children, and iconic signs appear to resist that reduction in sign length. It is possible that iconic signs are perceptually available longer, and their availability is a candidate hypothesis as to why iconic signs are overrepresented in children’s vocabularies. (shrink)