The interoceptive pattern in alexithymia is mixed, not a simple deficit
Interoception is not one ability. Researchers separate it into at least three parts: interoceptive accuracy (how well you can detect bodily signals like your heartbeat), interoceptive sensibility (how much you believe you are aware of internal sensations), and interoceptive awareness (the match between your actual accuracy and your beliefs about it). In a study of 182 people, higher alexithymia went with higher interoceptive accuracy and higher sensibility, but lower interoceptive awareness [3]. That means people with more alexithymic traits may actually be better at detecting bodily signals and more convinced they are aware of them, yet worse at aligning that confidence with their real performance.
This mixed pattern helps explain why simple claims that alexithymia means “poor interoception” are misleading. The same study found that interoceptive awareness was the strongest predictor of alexithymia, classifying alexithymia with over 92% accuracy in their sample [3]. The authors suggest that a disconnect between being accurate and being aware may be a core psycho-physiological mechanism, but that is an interpretation of correlational data, not a demonstrated cause.
Not all alexithymia components relate to interoception in the same way
Alexithymia itself has three parts: difficulty identifying feelings (DIF), difficulty describing feelings (DDF), and an externally oriented thinking style (EOT). In a network analysis of 504 people, DIF was the alexithymia component most strongly associated with interoception, while EOT was the least associated [1]. The same study found that high alexithymia was especially linked to a tendency to ignore sensations of pain or discomfort, whereas the personality trait neuroticism was more linked to worrying about those sensations [1]. So the interoceptive profile depends on which facet of alexithymia you look at and which other personality traits are present.
This nuance matters for interpreting any causal claim. If only some facets of alexithymia track interoceptive measures, a single causal pathway from “alexithymia” to “interoceptive deficit” is unlikely to capture the relationship. The network study suggests that some interoceptive deficits are shared with neuroticism and others are unique to alexithymia [1], which is consistent with a more complicated, possibly bidirectional, relationship rather than a simple one-way cause.
The strongest causal hint comes from a clinical sample, but it is still not proof
One study examined alexithymic schizophrenia patients and reported that reduced connectivity involving the anterior insula—a brain region important for sensing internal states—mediated the relationship between interoception and alexithymia [2]. A mediating pathway is the kind of pattern that could reflect causation: if brain connectivity changes explain why interoceptive ability and alexithymia go together, that would be a causal mechanism. However, the same paper explicitly notes that its observational design limits the ability to infer causation [2]. So even this neural evidence is a hypothesis about mechanism, not a demonstration that interoceptive deficits cause alexithymia or vice versa.
The clinical context also matters. Schizophrenia involves many brain and cognitive differences, so a pathway found there may not generalize to alexithymia in the general population. The study is best read as a clue that a causal pathway is biologically plausible, not as confirmation that one exists.
In some contexts, the interoception–alexithymia link weakens or disappears
A study of 337 young adult alcohol users found that alexithymia was not significantly correlated with most dimensions of interoceptive sensibility, and interoceptive sensibility did not mediate the link between alexithymia and alcohol use [4]. That contrasts with the idea of a general interoceptive deficit in alexithymia. The authors note limitations including self-report measures and a cross-sectional design, and suggest future work should test interoceptive accuracy rather than only sensibility [4].
Another study using a novel paradigm that separates sensory-driven from expectation-driven interoceptive processes found that alexithymia was characterized by attenuated prior precision—a larger divergence between expected and actual satiety, and low confidence in expectations—along with increased prediction error [5]. This is not a simple “deficit” but a difference in how bodily signals are weighted against expectations. Together, these findings suggest that the relationship between alexithymia and interoception depends heavily on which interoceptive process is measured and in which population.
Sources used in this answer
Shared and unique interoceptive deficits in high alexithymia and neuroticism
In a non-clinical sample, difficulty identifying feelings was the alexithymia facet most associated with interoception, externally oriented thinking was least associated, and high alexithymia was especially linked to ignoring pain or discomfort.
Aberrant anterior insula underlies interoceptive deficits in alexithymia among schizophrenia patients
In schizophrenia patients, reduced anterior insula connectivity mediated the relationship between interoception and alexithymia, suggesting a possible causal pathway, though the observational design limits causal inference.
Disentangling interoceptive abilities in alexithymia
Higher alexithymia was associated with higher interoceptive accuracy and sensibility but lower interoceptive awareness, and interoceptive awareness predicted alexithymia with over 92% accuracy.
Alexithymia and Alcohol Use: Evaluating the Role of Interoceptive Sensibility with the Revised Multidimensional Assessment of Interoceptive Awareness
Alexithymia was not significantly correlated with most dimensions of interoceptive sensibility, and interoceptive sensibility did not mediate the association between alexithymia and alcohol use.
Individual differences in sensory and expectation driven interoceptive processes: a novel paradigm with implications for alexithymia, disordered eating and obesity
Alexithymia was characterized by attenuated prior precision and increased prediction error in a paradigm separating sensory-driven and expectation-driven interoceptive processes.