- Published: November 30, 1999
There are interesting implications for the man whose frontal lobe tumor was responsible for the onset of pedophilia. He had never before shown sexual inclinations toward children, but the growth of a tumor correlated with the onset of those desires. When the tumor was removed, the desires and inappropriate actions subsided, and then returned when it grew back1.
This man and his family were probably relieved to have a biological abnormality to explain these actions, but a disturbing thought is that the tumor simply uncovered what was already “present” in this man’s brain. The frontal lobe is known to be involved in mediating restraint and social inhibition among other functions2. It is perfectly logical to postulate that the tumor (which would cause necrosis and metabolic starvation to the neural tissue surrounding it) depressed the functioning of this inhibitory area, thus releasing inherent urges. Certainly not every person with a brain tumor in the prefrontal cortex experiences these same pedophilic consequences, which would indeed help this man’s case (in that it would imply causality rather than an uncovering mechanism).
This does raise an unsettling question: if frontal inhibition masks certain undesirable tendencies, how many of us are animals inside? How many of us are not noble savages, but ignoble ones? What is our frontal lobe concealing in each of us? One possibility is that this man had always been cognizant of his abnormal sexual feelings and simply learned to suppress them. Although he reported otherwise, no one would want to admit previous feelings if a scapegoat tumor were available.
Our large frontal lobes separate us from animals anatomically, but functionally serve as masks of wild origins. Civilization depends on our frontal lobes, and allowed that ‘passage from the state of nature to the civil state” Rousseau mentions. The archetypal story of Phineas Gage’s transformation confirms that our actions are quite different without frontal inhibition, but the perversion unveiled in this particular case inclines me to believe that the man already struggled with this abnormal sexual appetite- whether it was conscious or not.
If people serving on juries knew (and really internalized) that the only thing preventing them from acting irrationally was a chunk of grey matter in the front of their brains, how would this change the way sentences were levied? People naturally make judgments of the accused based on the fact that they believe they would never commit such a crime. Perhaps explaining the very small matter that keeps them civilized would create juries that decide with more rational techniques, rather than a self-righteous confidence that it could never be them on the stand.
- Viskontas IV, et al. Symptoms of frontotemporal dementia provide insights into orbitofrontal cortex function and social behavior. Ann N Y Acad Sci. 2007 Dec;1121:528-45.