Having an impulsive personality means that you jump into situations without thinking through the consequences. Now scientists think they can see "impulsiveness" at work in the brain - and it looks a lot like potential drug addiction.
In a study published over the weekend in Science, a group of researchers described an experiment where they tested to see whether impulsive behavior was related to the neurotransmitter dopamine. Dopamine is associated with rash behavior, as well as the "high" people get from fun experiences - and various drugs. The researchers administered amphetamines to an experimental group, thus unleashing a dopamine cascade, and imaged their brains to see what happened to that dopamine in their brains.
People who scored high on a psychological test for impulsiveness tended not to absorb the dopamine because they had fewer dopamine receptors in their brains. These receptors "bind" dopamine and take it out of circulation. The impulsive subjects produced more dopamine in response to the drug, too.
What does that mean? The impulsive people got more of a "high" from the drug, partly because the neuroanatomy of their brains prevented them from binding the dopamine as quickly as less impulsive people. They also reported wanting more of the drug more frequently, too. Small differences in brain structure, in other words, can account for dramatic personality differences. It also means that we've got a potential model of what the brains of potential drug addicts look like.
But here's the real question: Does this mean a mad scientist could transform your brain into the brain of a potential addict, and then get you hooked on hamburgers? If that mad scientist could shut down dopamine receptors in your midbrain, then shoot you up with dopamine while you eat at McDonalds, then yes.
Read the full scientific paper via Science