A neuropsychological condition might explain the US president’s erratic behavior.

There have been numerous explanations for the seemingly erratic and unpredictable behavior of US President Donald Trump. He has made otherwise sober analysts turn apoplectic with rage, such as George Will of The Washington Post, who has called Trump a “venomous charlatan.” Others have labeled him a “puerile, sophomoric sniveler,” and psychiatrists have diagnosed Trump as having narcissistic, sadistic and paranoid personality disorders.

Three factors influence human personality. The first one happens to be genetic predispositions. The second is common environmental factors that influence all sibling behavior, such as the socioeconomic status of the parents. The third is unique environmental factors, such as an individual sibling being molested or bullied. However, human personality research concludes that the influence of genes is stronger than the other two factors combined.

In the case of Trump, his impoverished vocabulary, inexplicably poor grammar and an inability to produce a single coherent sentence belie his education. After all, he studied at Fordham University and the University of Pennsylvania — two schools that are not entirely useless. So is Trump a victim of his genes?

It is quite possible that the answer might be yes. This is indubitably a controversial statement, but let us examine the science behind it. The science of neuropsychology deals with brain behavior relationships and examines genetic predispositions in the cognitive domain. In neuropsychology, dysmetria — a Greek word that literally means “wrong length” — is a specific kind of ataxia. With this condition, a person loses control of motor function, unable to carry out an intended movement properly and tends to misjudge the target by overshooting it, undershooting it, or having an improper velocity or rate of the action. In 1991, neurologist Jeremy Schmahmann came up with a radical idea. He proposed that dysmetria of thought was as much a condition as dysmetria of action. In 2004, he coined the cerebellar cognitive affective syndrome (CCAS).

What is the cerebellum and why is it important in Trump’s case? The cerebellum means “little brain” or “lesser brain” in Latin. It sits it the back and bottom of the skull, below the rest of the brain, also called the cortex. The words “lesser brain” are actually ironic, as scientists estimate that of the 84 billion neurons in the entire brain, about 61 billion are crammed into the cerebellum. It has been known for centuries, if not millennia, that the cerebellum controls motor movements and their smooth sequencing. However, starting from the 1990s, there was evidence that the cerebellum “tweaks” thoughts just like it controls motor movements, and now three decades of cerebellum function research have clearly substantiated this claim.

Schmahmann was a pioneer in this field. He described CCAS as having four symptoms. First, the syndrome causes problems with executive functions such as poor planning, deficient abstract reasoning, working memory problems, decline in verbal fluency and trouble with multitasking as well as set-shifting. Second, this condition impairs visuospatial cognition, leading to disorganization and poor visuospatial memory. Third, CCAS leads to personality changes such as flattening or blunting of emotion as well as disinhibition and inappropriate behaviors. Fourth, it causes language difficulties, including trouble with prosody (melody, tone and quality of speech), word-finding difficulty and grammatical errors that cannot be attributed to a poor environmental upbringing.

Schmahmann also concluded that CCAS was associated with an overall lowering of intellectual functioning. It is important to note that Schmahmann developed the idea of this syndrome after studying patients with brain dysfunction as a result of strokes, tumors, brain atrophy or infections of the cerebellum — not upon non-clinical populations. Is it possible that Donald Trump is exhibiting CCAS without obvious cerebellar damage?

Although not proposed by Schmahmann, CCAS could be congenitally caused. This means that it could be genetically based or it could be a result of birth-related injuries. In other words, in people not suspected of cerebellar damage like Donald Trump, is it possible his speech fluency problems, deficient abstract reasoning, inappropriate and impulsive behaviors, poor grammar, strange word choices such as bigly, neologisms — coining of new words, like children and schizophrenic patients, such as covfefe — and his highly superficial exaggerations such as, big, great, fantastic, terrific, weak, bad, zero are all caused by subtle cerebellar compromise?

The views expressed in this article are the author’s own and do not necessarily reflect Fair Observer’s editorial policy.