The Blank Slate

In his bestseller, The Blank Slate, Steven Pinker argues that personality traits are inherited. They are the adaptive traits of our ancestors. When we are born, we are therefore not born as blank slates. Nor are we necessarily born good.

Certainly Dr. Pinker is onto something. We are born with lots of innate traits. But are we born with a particular unchangeable personality?

Cases of people who have undergone traumatic brain injury suggest that we aren’t.

I have examined several people who developed extraordinary abilities following brain injury. In each and every case their personality changed drastically.

For example, our most recent subject L, a 46 year old female, has literally become a different person after a dramatic accident. On October 11, 2009 she fell 40 feet down a 75 degree inclined steep slope, hit her head on numerous rocks, and sustained gashes from those impacts. She was flown to a trauma II hospital and had to have facial reconstruction and tooth implants.

After she recovered, things took a new turn. She emerged from the accident with new skills. She was previously a farmer. In fact, she was feeding chickens in Colorado when she fell down the steep slope.

After the incident she suddenly saw the world differently. She had no desire to look after farm animals, or any other animal for that matter. Instead she took up painting. She also writes poetry, quickly picks up foreign languages and has acquired perfect pitch.

What could possibly have happened in her brain in order for this transformation to take place?

Well, we know that subject L injured parts of her prefrontal cortex. The prefrontal cortex normally suppresses our creative skills. When this part of the brain is injured, the creative parts of the brain are free to flourish. This was most likely what happened to subject L.

What is perhaps even more amazing is the change in personality that occurred after the accident. Prior to the accident subject L was extraverted, the “class clown,” quick-witted, impulsive and not very conscientious. She lived to party and go out late at night with her best friend. She was also very good at sports but had no interests in the fine arts or any serious, intellectual matters, although she was fairly good at English in school.

After the accident subject L became a completely different person. Now she has no interest in farming or animals. She lives for her art: painting and poetry. But something even more drastic occurred. She no longer has emotions. She doesn’t feel fear, anger, irritation, joy or love. She would know that she ought to run if she were face to face with a tiger but she wouldn’t feel the fear that most of us would in the envisaged scenario. Her emotional responses are flat … with one exception: she has an amazing eye for aesthetic beauty. That is the closest to emotional feelings and responses that she ever experiences.

It is perhaps because emotions are needed to securely anchor most memories that subject L has difficulties remembering. She has had to learn what others feel. She has had to learn that her mother is her mother, that her brother is her brother and that people form relationships and get married. She doesn’t feel any of the feelings associated with these life-changing events. She has had to learn to give her friends compliments to avoid being rude but she never feels it. She is a new person, changed from a complex human being to an aesthetic creator and appreciator, without any other emotional biases.

Pinker, of course, is right that the idea of a blank slate is nonsense. But cases like that of subject L tells us that personalities can change radically, depending on how the brain is organized or rearranged.