                              A NEW THEORY OF ADHD
                            Russell A. Barkley, Ph.D.
        
             The current clinical consensus holds that ADHD is comprised
        of three primary symptoms: inattention, impulsivity, and
        hyperactivity. Inattention is often stressed as a primary feature
        of the disorder. Yet research on ADHD often finds that
        inattention is not reliably found in children with ADHD or does
        not distinguish the condition from other psychopathological
        disorders. This is not to say that those with ADHD are not
        observed to be ``off-task'' more, lower in persistence of effort,
        and less able to continue responding to assigned work--they
        surely are.  It is to say that formal laboratory measures of
        various components of attention do not reliably find the problems
        of those with ADHD to be in the realm of attention. Instead, the
        most consistent findings show a primary deficit in behavioral or
        response inhibition, the ability to delay responses, or the
        tolerance for delay intervals within tasks.  Thus, the primary
        component of ADHD is more one of disinhibition or poor delay of
        response than inattention. Most investigators working in the area
        of ADHD with whom I have spoken seem to agree with this
        assessment of the extant literature and its conclusions.
        
             Assuming for now that poor response inhibition or inability
        to delay response is the major hallmark of ADHD, how does this
        explain the myriad problems those with ADHD encounter in their
        academic, social, familial, emotional, occupational, and other
        domains of adaptive functioning? Why is such a deficit so
        debilitating to the successful adaptive performance of the
        individual in meeting the demands of daily social life? And how
        would this explain the poor organization and planning, poor sense
        of time management, deficits in mental arithmetic computation,
        delayed self-directed speech, immature social communication with
        peers, heightened emotionality, diminished problem-solving
        ability, limited sense of self-awareness, and delayed moral
        development, to name but a few of the deficits noted in ADHD
        children?
        
             I believe that an answer may rest within a theory proposed
        by Jacob Bronowski (1967/1977) over 25 years ago concerning the
        evolution of human language from other forms of primate social
        communication that led to several unique features of human
        language and cognitive abilities. [Bronowski was a distinguished
        mathematician, physicist, philosopher, and science writer most
        widely known for his book, The Ascent of Man, and the public
        television show based on this work in the late 1970s.  Like any
        new and useful theory, this one should better explain the
        findings in the literature on ADHD, accounting for findings not
        easily explained by existing theoretical models, such as those
        stressing attention. Moreover, it should direct our research and
        clinical attention to new areas worthy of exploration not
        previously thought relevant to ADHD. I believe that
        my extrapolation of Bronowski's theory to ADHD meets these
        requirements and provides a deeper understanding of the difficul-
        ties faced by those with ADHD in meeting the demands of daily
        adaptive functioning. It also seems to suggest that the impact of
        ADHD on daily living may be more pervasive than was once
        believed.
        
             BRONOWSKI'S THEORY OF DELAYED RESPONDING AND LANGUAGE
        
             Bronowski cogently argued that a major advancement in the
        evolution of human communication arose initially as an increase
        in the simple capacity to delay responses to a signal, message,
        or event.  The human capacity to delay responding vastly exceeds
        that of our nearest primate relatives by a quantum leap. This
        capacity to inhibit initial reactions to events, arising
        primarily from the expansion of the frontal lobes, permitted the
        later development of four uniquely human mental abilities:
        separation of affect, prolongation, internalization, and
        reconstitution. If ADHD represents a relative deficit in the
        development of delayed responding or response inhibition in the
        individual, as I believe, then these four mental processes should
        also be less proficient and less likely to guide or inform
        ongoing adaptive behavior than in those not deficient. The
        evidence that they are is quite compelling.
        
             Separation of Affect.  Bronowski argued that the delay in
        human responding permits the referral of the incoming signal,
        message, or event to more than one brain system at a time,
        allowing simultaneous processing of the event by multiple
        reference centers--the primary advantage of a large brain, he
        proposed. In so doing, humans are able to split the signal
        separately into its affective charge and its information or
        content. This capacity to separate feeling from fact, affect from
        content, and form from substance, permits humans to deal with the
        content of the message alone. All other species respond to these
        two features of a signal or message immediately and in total.
        Affect and content are one in the signal and in the response to
        it. In humans, the response delay permits the splitting of both
        the signal and the response to it into the separate features of
        content and affective charge. The ability to separate affect from
        informational content in signals and response permits humans the
        power of objectivity, perspective, logic, and rationality, as we
        ordinarily think of these attributes. It also ultimately
        underlies the human capacity for conducting science.
        
             If those with ADHD are less able to delay or inhibit
        responses to momentary signals or events, we should find them
        less able to utilize this downstream capacity for the separation
        of affect and thus less likely to have it inform and guide their
        ongoing adaptive behavior. They should react more often to the
        affective charge of a message or event than do others, and
        respond with greater intensity and range of affect as well. In
        short, they should prove more emotionally reactive to social
        situations than those without ADHD.
        
             They should also prove less objective in their assessment of
        the situation, more self-centered (less perspicacious), and less
        ``scientific'' or logical in their reactions to social
        situations, particularly those imbued with more affective signals
        than usual.  I and many others have been struck by just these
        social limitations in the behavior of those with ADHD seen in
        clinical situations.  Yet minimal research exists on the issue.
        
             Prolongation.  Bronowski reasoned that response delay also
        permits the signal to be more strongly and symbolically fixed
        mentally (working memory) through language and imagery. This has
        the effect of sustaining the mental existence of the stimulus
        during the delay long after the external event has passed into
        nonexistence in real time. This symbolic fixing of the signal
        permits time to refer or compare it with memory of other such
        events from which emerges our sense of past or hindsight. From
        this referencing backward in time and the manipulation of our
        recall of these past events in working memory derive our
        imagination and our sense of the future. The latter likely arises
        from our use of past events in memory to conjecture hypothetical
        futures. The consideration of such hypothetical futures leads to
        the formation of plans that propose action at a future time. 
        Through our communication with others we can then exchange such
        proposals or messages for future action--an ability seen in no
        other species. To summarize, the delay in responding permits a
        stronger, more lasting mental fixing of the signal from which
        springs hindsight, imagination, fore-thought, and our general
        sense of time--capacities apparently unique to our species.
        
             Again, my extension of this theory to ADHD would indicate
        that those with the disorder should be less proficient in the
        utilization of these capacities in view of their inability to
        delay responding. Failing to delay precludes the adequate usage
        of these mental abilities to glean information than can inform or
        guide ongoing adaptive behavior. After all, what is the point of
        using such capacities if the response to the signal or event is
        already released? It is too little, too late to guide adaptive
        behavior. If true, my application of this theory to ADHD points
        to a diminished sense of, or window on, time and its utilization
        in guiding behavior, a diminished sense of hindsight and
        forethought and their governance of current behavior, and a
        diminished capacity in those with ADHD to fix signals in working
        memory.  Could these deficiencies explain why those with ADHD
        show less learning from past experience (hindsight), greater
        forgetfulness (fixing of the signal), less concern for future
        events, and a diminished sense of time in the guidance of ongoing
        adaptive behavior?  Might it also explain the diminished capacity
        for performing mental calculations? I know of no research on
        these issues yet am impressed with how often I find such problems
        in the clinical presentation of my cases and how responsive ADHD
        adults are to my inquiring about them.
        
             Internalization.  Bronowski theorized that the imposition of
        a delay between signal and response permits humans to use
        language not only as a form of communication with others, as it
        is used by other species, but as a means of communicating with
        oneself.  In this process language is turned on the self and
        eventually internalized, permitting us the powers of reflection,
        rule formation, and the governance of behavior by such rules
        (plans, propositions for action) and, more generally,
        self-control.  This capacity for rule creation and rule-guided
        behavior, as Steve Hayes (1989) argued, frees humans up from the
        control of behavior by the moment (contingency-shaped behavior)
        or immediate context, and brings their behavior under the control
        of language, rules, plans or proposals for action.  In so doing,
        behavior becomes less variable, less subject to control by
        spurious or superstitious momentary consequences, more future
        oriented, less emotional (due to less exposure to
        contingency-shaping that results in more emotional
        reactions), and better suited to mediating long delays in
        schedules of consequences (deferred gratification). We can
        exchange these rules with others, providing the foundation for
        the transmission of culture (morals, mores, norms, policies,
        laws, and the wisdom acquired from past generations) to new
        generations.
        
             Applying Bronowski's theory to those with ADHD suggests that
        their inability to delay responding should result in less mature
        self-directed speech, diminished reliance on internalized
        language to control behavior, less utilization of reflection,
        diminished control of behavior by proposals for action (rules and
        instructions), especially in reference to a future time, and
        poorer self-control in general.  That moral development would be
        more delayed in those with ADHD is an obvious consequence as
        well.  Behavior in those with ADHD should be more variable, more
        controlled by momentary context, more emotional and
        contingency-shaped, less directed to future consequences, and
        less able to mediate delays between responding and later
        consequences.  Again, this seems to fit with research findings on
        self-directed speech, rule governance, and moral development in
        children with ADHD, and squares beautifully with what I see
        clinically as well.
        
             Reconstitution. Finally, Bronowski proposed that from the
        delay in responding and the internalization of language it
        permits we derive the abilities of analysis and synthesis. That
        is, we can deconstruct events and signals into parts,
        progressively redistributing them into particulars (objects,
        properties, actions) and progressively generalize their hortative
        content (proposals for action).  We can then reassemble these
        particulars into entirely new outgoing messages.  This not only
        underlies our dramatically superior powers of generative language
        but also of analysis and creativity (synthesis)--powers vastly
        expanded through this process of reconstitution.
        
             My generalization of this model to ADHD instructs us to
        consider whether those with ADHD are lessable to utilize these
        capacities in daily ongoing adaptive behavior than others. Are
        they less analytical, less capable of problem-solving on demand,
        and less given to synthesis or less creativity in coping with
        daily events?  I am not sure, and minimal research exists on the
        issue.  It seems highly worth a look.
        
                                  CONCLUSION
        
        My adaptation of Bronowski's theory of delayed responding to
        ADHD, in which an impairment in inhibition likely exists, seems
        to provide a more elegant explanation of existing research
        findings, a deeper appreciation for the pervasive impact of the
        disorder on daily life, and exciting suggestions for numerous
        future research explorations. Mind you, it is not that those with
        ADHD are incapable of separation of affect, prolongation,
        internalization, and reconstitution, but that the inability to
        delay response results in less utilization of, and reliance upon,
        these downstream mental abilities in informing and guiding
        ongoing responses.  Improve the capacity for delay and these
        downstream mental functions should act more proficiently,
        providing forward information to guide ongoing adaptive behavior.
        Evidence from recent studies (Berk & Potts, 1991) on stimulant
        medication suggests just such an improvement in these mental
        abilities when inhibition is increased by medication. And so it
        is not that those with ADHD do not think before they act so much
        as they act before permitting time to think. Rabelais was right: 
        ``Everything comes to those who can wait.''
        
        
                                 REFERENCES
        
        Berk, L. E., & Potts, M. K. (1991). Development and functional
             significance of private speech among attention-deficit
             hyperactivity disorder and normal boys. Journals of Abnormal
             Child Psychology, 19, , 357-377. 
        
        Bronowski, J. (1967). Human and animal languages. To honor Roman
             Jakobson (Vol. 1). The Hague, Netherlands: Mouton & Co.
        
        Bronowski, J. (1977). Human and animal languages. A sense of the
             future (pp. 104-131). Cambridge, MA: MIT Press.
        
        Hayes, S. (1989). Rule-governed behavior. New
             York: Plenum.
        
        
