Asymmetry occupies a remarkable position in the depth-psychology corpus: it functions simultaneously as a neurobiological datum, a cosmological principle, and a generative philosophical category. The dominant voice is Iain McGilchrist, whose treatment across both The Master and His Emissary and The Matter with Things elevates asymmetry from a mere structural feature of the divided brain to nothing less than the condition of possibility for novelty, life, and becoming itself. For McGilchrist, symmetry is sterile — an operation that leaves things unchanged — while asymmetry is generative, coupling disparate elements to produce something genuinely new. Crucially, the relationship between symmetry and asymmetry is itself asymmetrical, demanding both in dynamic conjunction rather than the dominance of either. The neurobiological literature represented by A.D. Bud Craig and Daniel Siegel grounds this philosophical argument in empirical detail: insular cortex lateralization, differential autonomic activation, and the presence of 30–50% more von Economo neurons on the right side of the frontoinsular cortex all speak to functional asymmetry as a constitutive feature of feeling, consciousness, and self-regulation. Siegel situates brain asymmetry within developmental relational frameworks, noting that its basis is laid in fetal stages. Across these voices a productive tension persists: is asymmetry primarily a structural brain fact, a cosmic generative principle, or the ontological ground of differentiation as such?
Asymmetry, by contrast, is generative – in more than one sense. First, asymmetrical operations produce not the same outcome, but something new.
McGilchrist argues that asymmetry is not merely the negation of symmetry but a positive, generative principle that produces novelty — cosmologically, biologically, and cognitively.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021thesis
Life is dominated by the effects of asymmetrical forces whose enveloping cosmic existence we sense intuitively. I would even say that living species are primordially, in their structure, in their external forms, functions of the cosmic asymmetry.
Drawing on Pasteur, McGilchrist frames biological life itself as a direct expression of a cosmos governed by asymmetrical forces, making asymmetry foundational rather than incidental.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021thesis
these conjunctions of opposites are not expressive of symmetry, but of the complementarity of elements that are fundamentally asymmetrical. This in turn helps one see that what is needed is both symmetry and asymmetry – themselves an asymmetrical pairing – together.
McGilchrist argues that the conjunction of opposites — including order and chaos, symmetry and asymmetry — is itself asymmetrical, making asymmetry the meta-principle that governs productive complementarity.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021thesis
these conjunctions of opposites are not expressive of symmetry, but of the complementarity of elements that are fundamentally asymmetrical. This in turn helps one see that what is needed is both symmetry and asymmetry – themselves an asymmetrical pairing – together.
Parallel passage confirming McGilchrist’s meta-argument that even the pairing of symmetry with asymmetry operates asymmetrically, placing asymmetry at the ontological ground of generative process.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021thesis
the assessment of symmetry or asymmetry is specifically right hemisphere-dependent – ‘a cognitive function lateralized to the right hemisphere for most of the population’.
McGilchrist grounds the perception of asymmetry neurologically in the right hemisphere, linking the generative philosophical concept to the specific cognitive architecture of global, holistic processing.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021thesis
the assessment of symmetry or asymmetry is specifically right hemisphere-dependent – ‘a cognitive function lateralized to the right hemisphere for most of the population’.
Parallel passage confirming the right hemisphere’s privileged role in detecting asymmetry, tying aesthetic, perceptual, and cosmological asymmetry to a unified neural substrate.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021thesis
As schizophrenic subjects are attracted to immobility, so they can become obsessed with symmetry. I have spoken about the ‘morbid geometrism’ displayed by many schizophrenic subjects. One aspect of this is an excessive need for symmetry.
McGilchrist uses schizophrenic pathology — characterized by excessive symmetry-seeking — as clinical evidence that the left hemisphere’s dominance suppresses the right hemisphere’s capacity to register generative asymmetry.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021supporting
As schizophrenic subjects are attracted to immobility, so they can become obsessed with symmetry. I have spoken about the ‘morbid geometrism’ displayed by many schizophrenic subjects.
Parallel passage identifying excessive symmetry-demand as a marker of left-hemisphere dominance and right-hemisphere dysfunction in schizophrenia, pathologizing the suppression of asymmetry.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021supporting
Neuroanatomical studies of the VENs (von Economo neurons) in the frontoinsular portion of the AIC in human cortex reported that there are 30% to 50% more VENs on the right side than on the left side.
Craig provides hard neuroanatomical evidence for structural asymmetry in the insular cortex, grounding the philosophical claim of hemispheric asymmetry in quantifiable cellular architecture linked to autonomic and affective function.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2014thesis
electrical stimulation of the right insula reportedly produces increased heart rate (tachycardia), whereas stimulation of the left insula produces decreased heart rate (bradycardia).
Craig demonstrates functional autonomic asymmetry mapped onto left-right insular distinctions, providing physiological evidence that the hemispheric asymmetry of feeling has measurable somatic consequences.
, How Do You Feel? An Interoceptive Moment with Your Neurobiological Self, 2014supporting
Cognitive and voluntary processes that attain maturity only after many years and that have special importance in cultural life tend to be asymmetric in the brain. The basis for this asymmetry seems to be set down very early, probably in fetal stages.
Siegel, citing Trevarthen, situates brain asymmetry developmentally, arguing that the lateralization underlying higher cultural and cognitive functions is established prenatally and elaborated through relational experience.
, The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are, 2020supporting
in schizophrenia, where a single side of the body was specified, in over 80% of cases it was on the left, suggesting right hemisphere dysfunction.
McGilchrist reports clinical data on lateralized somatic delusions, using the asymmetry of psychotic body-image distortion as evidence for differential hemispheric dysfunction in schizophrenia versus depression.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021supporting
in schizophrenia, where a single side of the body was specified, in over 80% of cases it was on the left, suggesting right hemisphere dysfunction.
Parallel passage confirming the lateralized pattern of somatic delusions as clinical evidence for asymmetric hemispheric contributions to bodily self-experience.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021supporting
brain asymmetry and, 263–265, 297–301
Siegel’s index entry locating brain asymmetry within the contexts of emotion regulation and relational development, confirming its systematic importance in his interpersonal neurobiology framework.
, The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are, 2020supporting
brain asymmetry and, 303
Siegel cross-references brain asymmetry with mother–infant interaction, indicating that hemispheric lateralization is treated as relevant to early relational and communicative processes.
, The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are, 2020supporting
Breaking symmetries of a certain kind in a similar way leads to irregularly regular ribbed patterns forming – eg, the stripes of a zebra: ‘there’s a hidden unity: the processes take different physical forms, but the patterns are universal’.
McGilchrist deploys Stewart’s mathematical examples of symmetry-breaking to illustrate how asymmetry drives the emergence of complex biological patterns from simpler symmetric conditions.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021supporting
Breaking symmetries of a certain kind in a similar way leads to irregularly regular ribbed patterns forming – eg, the stripes of a zebra: ‘there’s a hidden unity: the processes take different physical forms, but the patterns are universal’.
Parallel passage using the mathematics of symmetry-breaking to demonstrate that biological pattern formation depends on the generative introduction of asymmetry into prior symmetric conditions.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021supporting
we found that these were preferentially distributed to the left side of the body, suggesting that the neural basis of gestures develops independently from the development of the linguistic system
This infant research identifies a lateralized asymmetry in gestural expression, distinguishing the right-hemisphere gestural meaning-system from the left-hemisphere linguistic system in early development.
, The impact of early life trauma on health and disease the, 2010aside
This may be the link between cerebral lateralisation and creativity, and it may account for the otherwise difficult to explain fact of the relatively constant conservation, throughout the world, of genes which, at least partly through their effects on lateralisation, result in major mental illnesses
McGilchrist speculates that the conservation of genes promoting abnormal lateralization — and thus altered hemispheric asymmetry — may be evolutionarily linked to the benefits of creativity alongside the costs of psychopathology.
, The Master and His Emissary: The Divided Brain and the Making of the Western World, 2009aside