Temporal lobe epilepsy—a common form of epilepsy characterized by seizures that begin in the memory-regulating temporal lobe—does appear to influence personality, though not in the way many may think and certainly not in the way people have believed throughout history.

The idea of the epileptic personality is an ancient one. Thousands of years ago people with epilepsy were thought to be possessed by either divine beings or demons. In fact, the notion that a seizure represents a kind of communion with another spiritual realm still holds sway in some socie- ties today. In more recent history, Westerners largely perceived epilepsy as a punishment for morally lax behavior. In one 1892 paper, the author claimed that debauchery and excessive lust frequently led to epilepsy and that a person could trigger a seizure by listening to love songs and eating chocolate. More recently, scientists began investigating whether epilepsy, in fact, altered personality.

In 1975 neurologists Stephen Waxman and Norman Geschwind, both then at Harvard University, published an analysis based on observations of their patients with temporal lobe epilepsy in which they reported that many patients had a tendency toward religiosity, intense emotions, detailed thoughts, and a compulsion to write or draw. This cluster of characteristics became known as the epileptic personality. Over the next decade other researchers added hostility, aggression, lack of humor and obsessiveness to the list of personality traits supposedly associated with the condition.

By the 1980s, however, researchers began to question the notion of the epileptic personality altogether. They pointed out that the supposed core characteristics did not appear in all individuals with temporal lobe epilepsy and that many also occurred in other patient populations. By the end of the 20th century researchers came to a consensus that only a minority of temporal lobe epilepsy sufferers exhibited some of these core features.

In the meantime, psychologists working on theories of personality began to realize that although some aspects of character do have a biological basis, our natures are largely shaped by life experiences. Research shows that temporal lobe epilepsy may rewire the brains of some people, but by far the most significant influence will be how it changes people's outlooks or experiences.

Thus, the answer to the question is yes: having temporal lobe epilepsy will probably influence personality to a degree but mostly in the way that being diagnosed and coping with any serious condition might.

Question submitted by Claire Heptinstall via e-mail

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