Jane Hall's conceptualization of therapeutic work and the mechanisms of change aligns closely with my own understanding of psychoanalytic treatment. It also underscores the necessity of continually evaluating our theories of development, practice, and technique—distinguishing what remains valuable from what requires modification. My theoretical framework has evolved into developmental psychoanalysis, informed significantly by nonlinear dynamic systems theory. This perspective emerged from a longitudinal research project I initiated in the 1980s (Knight, 2005, 2011).
I undertook a longitudinal study to gain a deeper understanding of the developmental phase historically referred to as latency. Traditional descriptions characterized this period as one of relative calm and malleability—an image that starkly contrasted with the children I encountered in clinical settings. To investigate this discrepancy, I followed nine neurotypical boys and girls from age five to twelve, collecting annual psychological test data, structured interviews, parent and teacher questionnaires, and videotaped peer interactions.
Initially, my study design was based on psychosexual theory. However, upon analysis, the data did not conform to the conventional psychosexual model of latency. While some expected findings emerged, the children's psychological development displayed complexities that defied traditional conceptualizations. The data remained unexamined for years until I discovered nonlinear dynamic systems theory, which Thelen and Smith (1994) had employed in motor development research. This framework provided a way to reinterpret my findings and demonstrated how dynamic systems theory can enrich psychoanalytic understandings of development.
To illustrate the complexity of nonlinear dynamic systems, I will report several key developmental patterns identified in my research. Boys at age six and girls at age seven exhibited ego fragmentation, triggered by the confluence of separation-individuation processes, cognitive shifts, and hormonal fluctuations. Core internal structures, such as gender identity, became fluid, and both sexual and aggressive impulses intensified. By age eight, defenses described by Sigmund and Anna Freud (1936) reached sufficient maturity to manage these impulses. However, by age nine, these defenses unpredictably broke down, leading to a transient period of internal chaos. Projective testing revealed that children at this age displayed psychotic-like cognition, with conscious concerns about hallucinations and delusions.
At age ten, equilibrium was briefly restored before a subsequent fragmentation period emerged—particularly among girls entering pre-puberty. Notably, boys, who had not yet reached this hormonal stage, did not exhibit the same level of fragmentation, reinforcing the notion of distinct biological clocks for male and female development. By age eleven, both boys and girls navigating another phase of separation-individuation displayed depressive symptoms and suicidal ideation in projective testing, mourning the real and anticipated loss of childhood.
These findings suggest that development is neither linear nor predictable. Instead, it is characterized by cyclical disruptions and reorganizations—patterns observed across species, from primitive organisms to humans (Sander, 2002). Importantly, individuals rely on self-organizing and self-regulating structures, fostered within structured, supportive environments, to navigate these recurrent phases of disequilibrium.
For over three decades, research in neuropsychology, cognitive science, and socio-emotional development has demonstrated that psychological growth is shaped by dynamic interactions between biological, cognitive, and environmental factors. Thelen (1994) asserts, “Development can only be understood as the multiple, mutual, and continuous interaction of all levels of the developing system, from the molecular to the cultural.” My research substantiates this claim, illustrating how development
is fluid, nonlinear, and responsive to shifting internal and external conditions.
Periods of structural disorganization are not anomalies but essential components of growth. Stable cognitive, emotional, and biological configurations frequently destabilize, giving rise to transient fragmentation before new, more complex integrations emerge. Growth, therefore, is best understood through the increasing complexity and coherence of these reorganizing systems over time.
Another finding of my research is the occurrence of feelings of separation and individuation at many points in development not just in toddlerhood and adolescence. These feelings occur at every major developmental change: in toddlerhood, at the beginning of middle childhood, at the beginning of adolescence, at the beginning and end of emerging adulthood and throughout adulthood as people experience major biological/social/psychological changes and losses in their lives. Encountering these feelings in adulthood is not a regression but a reaction to the environment and their developmental age.
A significant implication of this model is that regression does not occur. Rather than a return to earlier developmental stages, each phase of psychological and cognitive development is incorporated into higher-order transformations. Consequently, psychoanalytic treatment must prioritize present-moment interventions that enhance flexible defenses, adaptive relational patterns, and evolving self-narratives that support continued developmental progression.
This research supports a nonlinear dynamic systems approach to development, challenging longstanding notions of predictable, stage-based progression. It suggests that normal development is best understood as continuous disequilibrium, extending from infancy through adulthood—occurring during periods in which biological and psychological transformations remain in flux. Adolescence and emerging adulthood, in particular, exemplify nonlinear reorganization, as the brain and body undergo further dramatic changes.
A dynamic systems approach points out an important flaw in all the early theories about development, one that carries on today in other more contemporary theories of development. That is the idea of development being unduly influenced by the first two years of life—the overly influential relationship between the baby/toddler and her mother—leaving out the importance of the father, siblings, extended family, caretakers, teachers and peers, and the present and changing environment and culture on the continual psychological development of the infant, child, adolescent, emerging adult and adult.
One might ask how thoughts and mental representations are formed using a dynamic systems theory. Children initially perceive and internalize patterns of behavior from the people in their environment. As this social system develops, children make clear predictions about occurrences in their world and other people's actions based on their recognition of their own learned social behaviors and observations of the physical world. Representations held in memory reflect the structure of the environment and the temperament of the child because they are mapped to one's perceptions of the outside world. This allows internal representations to become meaningful in and of themselves through their use in interpreting the environment, making the child's thoughts and actions central to his understanding of the world he lives in. This is how conscious narratives are formed as the child, adolescent, emerging adult and adult continue to develop. It also makes clear the importance of working with the family to understand the mindset and interactions that the child and adolescent has observed and learned from.
Intelligence, internal representations, fantasies, morality and the unconscious can then be understood through an integrative perspective of the environment, the body and the mind and the degree to which these complex dynamic systems can stably engage and flexibly switch over a certain period of time. With the idea of systems continuously changing we can begin to study the ways in which the development of self and self-other representations, sexual and aggressive feelings, ego structures and moral development both change and interweave during every phase of development.
Stability and flexibility are both important if psychological growth is to occur. A system that is too variable would not be adaptable, because
stability is necessary for change to have a chance to stabilize and reorganize. But a system that is too stable can result in constriction that does not allow for change and growth.
Each person brings her own innate strengths and vulnerabilities the physical, dispositional, neurobiological, and relational—to respond to and act upon the environmental system, all working together in a continuous reorganizational flow and transformation. Thus, it is the interaction of multiple systems that continually act in concert and change over time that evolve in the course of development. All phases of development are predominantly in a state of fluid linear and non-linear transformation that can be continuous and discontinuous. Through each stage of development there is a fragmentation period in which old structures break down and are changed by biology and the environment which includes their family and the culture of the time they are living in. Development is messy. It is filled with novelty and complexity, with both parallel and interacting processes. Major cognitive and biological changes are continually transforming a person's mind and body. Relational and environmental changes occur from infancy through old age. Culture is continually changing and influences development and a sense of self and other.
A dynamic systems theory allows analysts more freedom of thought. When I have presented this theory, I have heard more than one analyst say to me that they finally understood why they never felt comfortable with psychoanalytic theory—it felt too constricting in their work—and that a dynamic systems theory gave them permission to think more flexibly about all aspects of a patient's life.
Another advantage of this theory is that it supports the idea of people continually changing and growing throughout their life span. If we are flexible within ourselves and in our interactions with the world—both relationally, socially and culturally—our psychological/biological/cognitive systems are never “set” at a particular time in development. When I teach this to candidates, they are always relieved and hopeful because this theory recognizes that continual change is possible throughout development and makes the idea of change in analytic treatment achievable.
Conceptualizing development as a nonlinear dynamic system alters the way we think about the developmental organization of each person we
work with and the treatment that will best help them. This requires us to give up the comfort of what we know and sit with the possibilities that arise with not knowing. Rather than focus on genetic determinants and think of present-day analytic interactions as “regressive,” I suggest that we attend to and analyze the observable interaction in the analytic relationship in the present, that can influence further development and be influenced by further development. Our job then becomes one of helping change our patient's story about him or herself by helping them reflect on what is preventing them from flexibly adapting to present and future developmental fluidity and reorganization. In this way, we can co-create a new narrative that promotes transformation and a more flexible and resilient development. Successful adaptation to biological, psychological, and environmental changes necessitates the capacity for flexible responses and the endurance of developmental disequilibrium. Novick and Novick (2003) conceptualize this adaptability through a two-system model: a closed system resists change, maintaining rigid defenses, while an open system accommodates new experiences, fostering ego resilience and developmental progression. From this perspective, persistent symptoms and character rigidity may indicate developmental pathology rather than stability.
Using dynamic systems theory and what we know about development helps our understanding and treatment of the children, adolescents, emerging adults and adults whom we treat. Sam Abrams (2003) suggested a non-hierarchical partnership in discovering, one in which the interpersonal “reflects an operational feature of the treatment relationship, [and] the intrapsychic defines how that operational feature is experienced in the minds of both participants.” This definition is in keeping with Robert Galatzer-Levy's (1995) suggestion that operational descriptions devoid of semantic definitions like “mother” and “infant” are more likely to allow complex systems to arise from a dyadic exchange that is often filled with periods of disorganized, messy, not knowing that both participants have to tolerate.
Out of this interchange the analysand and the analyst are free to make new discoveries that are very particular to both people in the dyad. This is a model that rather than looking backward to genetic interpretation, looks forward to new developmental, emergent growth—something child analysts have always done but can also serve as a model for adult
analysis. It requires keeping an eye on the present and the future rather than to experiences of the past or the nature of the equipment alone. While genetic interpretations might provide a narrative that gives a person a sense of continuity, they may not be accurate, and, more importantly, they short circuit a necessary understanding of the unconscious dynamics that are the product of interactional systems that help a person cope with their present life situation, for better or worse.
This way of looking at development complicates the task of understanding each patient in analysis since there is no prevailing central narrative, nor an expectable sequence that can be tracked. It requires each analysis to be a novel understanding, a novel narrative that is different for every person and analytic pair. The analytic relationship helps our patients make increasingly complex and coherent meanings of themselves, the analytic relationship and the environment in which they live. Each analysis becomes a process of discovery, a puzzle to be understood that is tailored to each individual we treat.
Treatment becomes a transforming and transformative partnership exploring the multiple determinants of psychological thinking and behavior, with the aim of bringing together an adaptive narrative that serves ongoing and future needs and values. This was Anna Freud's distinction between the developmental and genetic points of view.
Feeling understood by the analyst and understanding the analyst assists in the organization of the patient's feelings and thoughts. Feeling understood also provides a new level of relational and intrapsychic integration as the patient assimilates the understanding of new thoughts and feelings within the co-constructed narrative. The child or adult can then accommodate old systems of feeling and thinking to the new information, which leads to further development through structure building. Helping patients construct a narrative through play encourages the development of mentalization, facilitating the understanding and internal representation of self and other and furthers brain development.
Shifting to a nonlinear model requires relinquishing the assumption of orderly, stage-based progression. In return, we gain a framework that better accounts for the complexities of psychological development, paving the way for innovative clinical approaches. Embracing developmental
ambiguity not only fosters new psychoanalytic research avenues but also refines our clinical understanding of “normal” progression.
From a treatment standpoint, conceptualizing development as a nonlinear process alters how we work with child, adolescent, and adult patients. Rather than focusing on genetic determinants or interpreting analytic interactions as regressive, I propose that we center our interventions on the observable present-day narrative. This includes examining how patients construct their self-understanding in relation to others and how these narratives shape ongoing development. Our task as analysts is to co-construct new narratives that expand the patient's adaptive capacities, helping them navigate future developmental reorganizations with greater fluidity.
NLDST goes beyond psychoanalysis, providing a framework that connects multiple disciplines. To keep psychoanalysis relevant in our rapidly changing world, we must engage with related fields. Neuroscience provides critical insights into the biological foundations of behavior, including the role of neuroplasticity in adaptation and growth. Developmental psychology contributes empirical research on attachment, learning, and resilience among others, while cultural studies enrich our understanding of the sociocultural contexts in which development occurs. Collaborating with researchers from these disciplines helps ensure that psychoanalytic theories stay scientifically valid and applicable.
By integrating these diverse perspectives, NLDST ensures that psychoanalytic theory remains scientifically grounded and clinically effective. This interdisciplinary approach not only enhances the validity of psychoanalytic models but also expands their applicability to diverse populations and contexts. As psychoanalysis embraces this modern framework it positions itself as a forward-looking field capable of addressing the complexities of human growth across the lifespan, ensuring that our field remains a vital and impactful discipline for understanding and supporting human potential.
By integrating nonlinear dynamic systems theory into psychoanalytic developmental theory, we gain a richer, more nuanced understanding
of psychological growth. Recognizing development as an iterative process of organization, disorganization, and reorganization enables clinicians to more effectively address patients' adaptive and maladaptive responses to change. Rather than viewing psychological stability as the absence of disruption, we must reconceptualize it as the capacity to endure and integrate change—a shift that has profound implications for both psychoanalytic research and practice.