Phineas Gage: His Accident and Impact on Psychology

Phineas Gage was a 25-year-old railroad foreman who survived an iron rod being driven through his skull and left frontal lobe in 1848. His reported personality change afterward, from capable and even-tempered to impulsive and unreliable, made this one of psychology’s most famous case studies.

What Happened To Phineas Gage?

On September 13, 1848, Phineas Gage, a 25-year-old railroad construction foreman, was preparing explosives in Cavendish, Vermont.

As he tamped down blasting powder with a 43-inch, 13-pound iron rod, the charge exploded unexpectedly.

The tamping iron shot through his left cheek, behind his eye, and out through the top of his skull, destroying much of his left frontal lobe.

Amazingly, Gage survived. He remained conscious, was able to speak, and even walked unaided to a cart that took him to the local doctor.

Dr. Edward H. Williams noted that Gage’s brain was visibly pulsing through the wound. Gage, showing grim composure, greeted him with words to the effect of “here is business enough for you.”

Recovery and the First Clues of Change

Dr. John Martyn Harlow later took over Gage’s care. Though Gage suffered infections and a semi-comatose spell, he steadily recovered.

By October, he was walking and talking again. Physically, he appeared to regain his strength. Mentally and emotionally, however, something had changed.

Before the accident, Gage was described as energetic, responsible, and a favorite among his crew. Afterward, reports painted him as impulsive, rude, and unreliable.

Harlow wrote that “the equilibrium or balance… between his intellectual faculties and animal propensities, seems to have been destroyed.” He added:

“He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom)… at times pertinaciously obstinate, yet capricious and vacillating… devising many plans… which are no sooner arranged than they are abandoned… A child in his intellectual capacity and manifestations, he has the animal passions of a strong man”.

His friends famously said he was “no longer Gage.”

How Much Did Gage Really Change?

Though Harlow’s accounts are the primary source of information, later writers often embellished Gage’s personality both before and after the accident.

Some described him as unusually polite and mild-mannered pre-accident, and almost monstrously unstable afterward.

Accounts often idealise Gage’s character before the accident. The post-injury version is then exaggerated into near caricature, unlike Harlow’s own measured clinical account.

This embellishment likely reflects enthusiasm for making Gage’s case fit localization theories. Macmillan (2000) warns that such dramatised descriptions need cautious handling.

Harlow also recorded that Gage later held a demanding job as a stagecoach driver in Chile. Such sustained, responsible work suits no severely incapacitated man.

The photographic record backs this up. Daguerreotype portraits of Gage were only identified as genuine in the twenty-first century. They show him well-dressed and composed, holding his inscribed tamping iron, not the dishevelled wreck of popular legend (Macmillan & Lena, 2010).

Severity of Gage’s Brain Damage

In the 1990s and 2000s, researchers used neuroimaging and CT scans to reconstruct Gage’s skull and estimate the trajectory of the rod.

Later work refined this picture. Hanna Damasio and colleagues (1994) tackled this by photographing and measuring Gage’s skull, then using computer modelling to simulate the rod’s likely trajectory. They concluded that the damage reached the ventromedial prefrontal cortex in both hemispheres.

This region, the front-most part of the frontal lobe, is involved in emotional processing and real-world decision-making. The two teams reached different verdicts.

Ratiu et al. (2004) used thin-slice computed tomography (CT) of the skull to build three-dimensional reconstructions of the injury. The picture looked different this time. They found that the damage was limited to the left frontal lobe and did not cross into the right hemisphere (see Fig. 2).

Van Horn et al. (2012) agreed with Ratiu et al. (2004) that the rod damaged only the left frontal lobe, not the right.

Van Horn’s team also found that Gage likely lost 11% of his white matter and 4% of his grey matter. This was enough to affect thinking and behavior, but not to prevent functional recovery.

A different question emerged.

Some researchers speculated that Gage’s behavioral changes might resemble early-onset Alzheimer’s, since both involve white matter degradation. However, Harlow only reported on Gage shortly after the accident, and there’s no concrete evidence he developed the disease. This remains purely speculative.

Why the Exact Damage Remains Unknown

Every study of Gage’s brain damage involves speculation. We cannot know for certain how much damage the accident itself caused.

We know that some brain tissue was destroyed, but any infections Gage suffered afterward may have destroyed further tissue.

We also cannot pinpoint exactly where the rod entered. Brain structure varies from person to person, so researchers can never know for certain which areas of Gage’s skull were destroyed.

What Happened to Phineas Gage After the Brain Damage?

Gage eventually moved to Chile and worked as a stagecoach driver. In 1860, he returned to the U.S. and began experiencing epileptic seizures.

He died in San Francisco in 1860. That was around twelve years after the accident, from complications linked to epilepsy.

In 1867, Harlow arranged to exhume Gage’s body and recovered his skull and tamping iron. Both are now held at Harvard’s Warren Anatomical Museum.

Why Is Phineas Gage Important to Psychology?

Launching Neuropsychology and Localisation of Function

Gage’s story helped launch the field of neuropsychology. It provided early, powerful evidence that the frontal lobes are essential for regulating behaviour, personality, and social functioning in everyday life.

It also introduced the idea of localization of brain function: that specific parts of the brain serve specific roles. That idea reshaped psychology.

Gage arrived at exactly the right moment for this idea to take hold. The case predates Paul Broca’s speech-area findings by roughly a decade, when the debate between localisation and an undifferentiated, whole-brain view of the mind was still wide open.

His selective pattern of loss fits neither an all-purpose brain nor old-style faculty psychology, which is why the case still comes up wherever localisation of function is taught. Students often meet it first.

Evidence of Recovery and Neuroplasticity

Yet Gage’s case is not just a tale of loss. His return to functional life suggests the brain’s remarkable capacity for neuroplasticity.

As Macmillan (2002) argues, Gage may have relearned lost abilities over time. He adapted. This is an early, striking example of resilience after brain injury.

This fits what we already know about his later life: years of demanding, routine-based work as a stagecoach driver in Chile (see How Much Did Gage Really Change?, above). Routine, structured demands may have supported this kind of relearning, giving the brain repeated practice at planning and self-regulation.

That is a modest but real form of recovery.

Frontal-Lobe Syndrome and the Somatic Marker Hypothesis

Gage still matters to modern neuroscience. The case gave clinicians a name for what is now called frontal-lobe or dysexecutive syndrome. This is damage to the ventromedial prefrontal cortex that leaves intelligence and memory intact but disrupts planning, emotional control, and socially appropriate behavior.

This connects directly to modern research. Antonio Damasio’s somatic marker hypothesis proposes that the ventromedial prefrontal cortex binds emotional signals to reasoning, tested using tasks such as the Iowa Gambling Task. Gage is considered the historical starting point for this entire line of research linking emotion to rational decision-making.

Gage remains a teaching touchstone for the prefrontal cortex’s role in personality and decision-making. It is a story everyone in psychology eventually meets.

He is also a byword for both the power and the pitfalls of case-study evidence, one of the most recognisable stories in the public understanding of neuroscience.

Critical Evaluation of the Phineas Gage Case Study

Gage’s case is both foundational and famously fragile as evidence. AQA and other exam boards often ask students to evaluate it directly, so the strengths and weaknesses below are worth knowing by name.

1. No Control Group: As a single case study, Gage offers no comparison group, so the link between his injury and his behaviour can only be inferred, not proven.
2. A Thin, Retrospective Record: The fullest account of his personality change was written twenty years after the accident, drawing on other people’s memories rather than contemporaneous notes.
3. No Imaging in Gage’s Lifetime: Every modern claim about which brain regions were destroyed rests on a 19th-century skull, not a scan taken while Gage was alive.
4. Genuine, Lasting Influence: Despite these flaws, the case genuinely launched the study of brain-behaviour links and still converges with modern research on emotion and decision-making.
5. A Contested Explanation: Even Harlow’s own account may not need a neurological explanation at all; one historian argues the change reflects Gage’s reaction to disfigurement, not brain damage.

Why One Case Can’t Prove Causation

Some limitations cut deeper than others.

Gage was a natural experiment, an event that occurs naturally rather than one a researcher deliberately creates, not a designed one. No matched colleague stayed uninjured as a comparison.

That absence of a control group and of any experimental manipulation means the link between his wound and his behaviour can only be inferred, never proven outright.

Case studies like this one are excellent for generating ideas but weak for testing them. Brain organisation differs from person to person. A change seen in one patient might reflect that patient’s own biology, not a general rule about the frontal lobes.

No two brains are organised identically.

This is why later researchers, including Malcolm Macmillan, treat Gage’s case study as a starting hypothesis. It is not proof that frontal damage reliably produces one particular personality profile. This is a hypothesis, not a verdict.

A Record Written Twenty Years Late

Dr. John Martyn Harlow, Gage’s own physician, wrote the fullest account of the personality change in 1868. That was twenty years after the accident and eight years after Gage had died. Harlow drew heavily on the recollections of Gage’s family and acquaintances rather than on notes taken at the time.

Eyewitness memory fades fast.

Memory reshapes itself around expectation. Later writers went further still, polishing Gage’s pre-accident image into that of a model citizen while darkening his post-accident behaviour into near caricature. Neither extreme matches Harlow’s own, more measured clinical language.

Not every contemporary observer told the same dramatic story. Henry Jacob Bigelow, the Harvard surgeon who examined Gage in person, presented the case to the medical profession (Bigelow, 1850).

Bigelow was comparatively sceptical of the more sensational claims, a counterweight often left out of popular retellings. That disagreement between eyewitnesses is itself a reason for caution.

One Skull, No Living Scan

There was no neuroimaging and no formal neuropsychological testing while Gage was alive. Everything modern researchers know about the lesion comes from his skull, exhumed and measured decades after his death.

That creates two problems. Reconstructions must assume a ‘standard’ brain, even though real anatomy varies from person to person. Infection after the accident may also have destroyed additional tissue beyond what the rod itself damaged, further blurring the picture.

That gap matters for interpretation.

The reconstructions disagree because of this uncertainty. Damasio and colleagues modelled bilateral damage. Ratiu and colleagues, and later Van Horn and colleagues, concluded the injury was confined to the left hemisphere instead (see Severity of Gage’s Brain Damage, above).

Even the basic location of the damage remains contested. That is a shaky foundation for the many strong claims built on top of it.

A Case That Still Shapes the Field

Despite every limitation above, Gage’s case is not merely a cautionary tale. It helped launch neuropsychology, the practice of inferring normal brain function from patients with brain damage, alongside Paul Broca’s work on language and, later, the amnesic patient H.M.

The case also converges with modern research. Antonio Damasio’s somatic marker hypothesis points to a similar picture. So does decades of work on the ventromedial prefrontal cortex and decision-making (see Why Is Phineas Gage Important to Psychology?, above).

Both describe intact intellect paired with impaired judgement after this kind of damage. A purely mythical story would be unlikely to converge with real modern data this way.

Gage himself complicates the simplest reading. He later held a demanding stagecoach-driving job in Chile for several years, suggesting real functional recovery rather than permanent ruin. The fair verdict treats Gage as a historically pivotal, suggestive case: genuinely useful, and just as genuinely limited.

A Rival Explanation: Psychological Reaction, Not Brain Damage

Not every scholar accepts that Gage’s changed behaviour came directly from his damaged frontal lobe. Psychologist Zbigniew Kotowicz (2007) disagrees.

He argues that Harlow’s own descriptions never really support a full “psychopathic” transformation. Gage’s later life looked restless: frequent moves, and a string of short-lived jobs. Kotowicz reads this as a psychological reaction to disfigurement and stigma, not a damaged brain.

The injury still matters here. Without it, Gage’s disfigurement and its social fallout would not exist. Kotowicz simply relocates the cause: not damaged circuitry, but a man adjusting to how people now saw him.

Kotowicz frames the stakes bluntly. He sees the standard reading as part of a wider habit in brain-based psychiatry: swapping a person’s own biography for a brain-mechanism story.

Contemporary Research

Research since 2015 has sharpened the anatomical picture and tested the modern claims built on Gage’s case.

Tractography and Gage’s Disconnected Networks

Aim: Building on earlier connectome work, Thiebaut de Schotten et al. (2015) revisited Gage’s lesion. Their question: disconnection, or local damage?

Method: They combined a computed tomography scan of Gage’s skull with the recovered tamping iron’s dimensions to model the rod’s path. This model was then overlaid on a tractography-based map of white-matter connections from 129 healthy adults.

Results: At first glance, the damage looked entirely local: orbitofrontal, dorsolateral prefrontal cortex and temporal pole cortex.

But the tractography told a bigger story. Major fibre tracts were disrupted well beyond the visible lesion, reaching structures such as the amygdala and cingulate cortex, far from the rod’s actual path.

Conclusion: The authors argue this widespread disconnection, not the local damage, better explains the breadth of Gage’s reported personality change. Damage in one place; disruption everywhere.

Evaluation: This is the strongest anatomical reconstruction available, but it remains a model fitted to one 170-year-old skull. No behavioural testing exists to confirm that these specific tracts caused Gage’s reported changes.

That still leaves an open question.

Is the VMPFC Really Necessary for Decision-Making?

A 2023 systematic review puts a number on this question. Messimeris and colleagues reviewed group studies of ventromedial prefrontal cortex damage published between 1990 and 2023, testing patients on value-based and social decision-making tasks.

They found consistent evidence that the region helps people learn and update the value of rewards. Its role in decision-making itself, though, looked moderate and context-specific rather than strictly necessary.

Social judgement fared no better. VMPFC damage impaired how patients represented other people’s rewards, but effects on fairness and cooperation judgements were inconsistent.

The picture that emerges is a key motivational node, not an indispensable switch (see Why Is Phineas Gage Important to Psychology?, above, for Damasio’s somatic marker hypothesis). Gage’s case still points to the frontal lobes; it just no longer supports an all-or-nothing story.

How Textbooks Tell the Gage Story

Griggs (2015) tested how the textbooks themselves handle this. He analysed 23 introductory psychology textbooks and found 21 covered Gage’s case, usually getting the accident and injury right.

Recovery told a different story. Only about half discussed what happened to Gage afterwards, and very few mentioned the photographic evidence or the digital lesion reconstructions published since 2004.

The pattern fits. Textbooks tend to repeat the dramatic, incomplete version of Gage and under-report the recovery that complicates it, echoing the embellishment problem already described above.

References

Bigelow, H. J. (1850). Dr. Harlow’s case of recovery from the passage of an iron bar through the head. American Journal of the Medical Sciences, 20(39), 13–22.

Blakeslee, S. (1994, July 6). A miraculous recovery that went wrong. New York Times.

Damasio, H., Grabowski, T., Frank, R., Galaburda, A. M., & Damasio, A. R. (1994). The return of Phineas Gage: Clues about the brain from the skull of a famous patient. Science, 264(5162), 1102–1105.

Harlow, J. M. (1848). Passage of an iron rod through the head. Boston Medical and Surgical Journal, 39(20), 389–393.

Harlow, J. M. (1868). Recovery from the Passage of an Iron Bar through the Head. Publications of the Massachusetts Medical Society. 2 (3), 327-347.

Kao, Y. H., Chou, M. C., Chen, C. H., & Yang, Y. H. (2019). White matter changes in patients with Alzheimer’s disease and associated factors. Journal of Clinical Medicine, 8 (2), 167.

Kotowicz, Z. (2007). The strange case of Phineas Gage. History of the Human Sciences, 20(1), 115–131. https://doi.org/10.1177/0952695106075178

Lahey, B. B. (1992). Psychology: An introduction. Wm. C. Brown Publishers.

Macmillan, M. (2000). Restoring Phineas Gage: A 150th retrospective. Journal of the History of the Neurosciences, 9(1), 46-66.

Macmillan, M. (2002). An odd kind of fame: Stories of Phineas Gage. MIT Press.

Macmillan, M., & Lena, M. L. (2010). Rehabilitating Phineas Gage. Neuropsychological Rehabilitation, 20(5), 641–658.

Messimeris, D., Levy, R., & Le Bouc, R. (2023). Economic and social values in the brain: Evidence from lesions to the human ventromedial prefrontal cortex. Frontiers in Neurology, 14, Article 1198262. https://doi.org/10.3389/fneur.2023.1198262

Myers, D. G. (1998). Psychology (5th ed.). Worth Publishers.

Nasrabady, S. E., Rizvi, B., Goldman, J. E., & Brickman, A. M. (2018). White matter changes in Alzheimer’s disease: a focus on myelin and oligodendrocytes. Acta neuropathologica communications, 6(1), 1-10.

Ratiu, P., Talos, I. F., Haker, S., Lieberman, D., & Everett, P. (2004). The tale of Phineas Gage, digitally remastered. Journal of neurotrauma, 21 (5), 637-643.

Suinn, R. M. (1970). Fundamentals of behavior pathology. Wiley.

Thiebaut de Schotten, M., Dell’Acqua, F., Ratiu, P., Leslie, A., Howells, H., Cabanis, E., Iba-Zizen, M. T., Plaisant, O., Simmons, A., Dronkers, N. F., Corkin, S., & Catani, M. (2015). From Phineas Gage and Monsieur Leborgne to H.M.: Revisiting disconnection syndromes. Cerebral Cortex, 25(12), 4812–4827. https://doi.org/10.1093/cercor/bhv173

Van Horn, J. D., Irimia, A., Torgerson, C. M., Chambers, M. C., Kikinis, R., & Toga, A. W. (2012). Mapping connectivity damage in the case of Phineas Gage.
PloS one, 7(5), e37454.

Further Reading

• Griggs, R. A. (2015). Coverage of the Phineas Gage Story in Introductory Psychology Textbooks: Was Gage No Longer Gage?. Teaching of Psychology, 42(3), 195-202.
• Wilgus, J., & Wilgus, B. (2009). Face to face with Phineas Gage. Journal of the History of the Neurosciences, 18(3), 340-345.
• Macmillan, M., & Lena, M. L. (2010). Rehabilitating Phineas Gage. Neuropsychological Rehabilitation, 20, 641–658.
• Macmillan, M. (2000). Restoring phineas gage: a 150th retrospective. Journal of the History of the Neurosciences, 9(1), 46-66.
• Kotowicz, Z. (2007). The strange case of Phineas Gage. History of the Human Sciences, 20(1), 115-131.
• O”driscoll K, Leach JP. “No longer Gage”: an iron bar through the head. Early observations of personality change after injury to the prefrontal cortex. BMJ. 1998;317(7174):1673-4. doi:10.1136/bmj.317.7174.1673a