Carolyn GregoireSenior Health & Science Writer, The Huffington Post
Now, provocative new research from Oxford University suggests that something akin to this theory of intelligence might even help to explain a person's income bracket, education level, and happiness. The study, which was published online Sept. 28 in the journal Nature Neuroscience, finds that happy, successful people who make positive life choices all showed greater connectivity in brain regions associated with high-level cognition.
For the study, Oxford neuroscientists used data from the Human Connectome Project -- a $30 million brain imaging project funded by the National Institutes of Health -- to compare the functional MRIs of 461 people with in-depth personality, demographic and lifestyle data they'd provided the researchers. The participants had taken personality tests and answered questions about themselves so they could be scored on variables including life satisfaction, income, education, memory, vocabulary and general personality traits that most people consider beneficial -- for example, resilience and positivity.
The researchers used data from the MRIs to create an average map of neural connections across all of the participants' brains. Then, for each individual participant, they analyzed how different regions of the brain communicated with one another, and compared these connections with data about the subject's personality and lifestyle.
The researchers found that people who scored higher in positive measures of lifestyle and behavior had stronger functional connectivity between brain regions associated with memory, language, imagination and theory of mind (the ability to attribute mental states to oneself and others). Those who scored higher on negative measures of personality and lifestyle -- including anger, rule-breaking, substance abuse and poor sleep quality -- tended to have weaker connections.
"We found that variation in brain connectivity and an individual's traits lay on a single axis -- where people with classically positive lifestyles and behaviors had different brain connectivity to those with classically negative ones," Stephen Smith, a biomedical engineer at Oxford and the study's lead author, told The Huffington Post in an email.
"The main finding from the brain imaging data is that ... this 'positive-negative' axis, combining many aspects of an individual’s life, experience and abilities, is imprinted in the brain," Smith said.
The researchers were able to place each individual participant somewhere along this "positive-negative" axis based on their brain connections, which in turn predicted other traits and lifestyle information.
What does it all mean? Well, it seems that an individual's unique neurobiology, personality traits and life circumstances may be more connected than we've generally believed. This suggests that personality traits don't exist in a vacuum, but may be part of a more holistic picture of who a person is.
There are still many questions to be answered -- the study didn't prove causality, so we don't know if the brain connections caused differences in lifestyle and behavior, or vice versa. The findings also don't mean that we're somehow hard-wired to have positive or negative traits.
"Although this study reports an interesting connection between patterns of brain connectivity and lifestyle/behavioral measures that is present in general in the population, it is still the case that every person is a distinct individual who does not exactly follow this general pattern in every fine detail," Smith noted.
To learn more about the work of Oxford's Centre for Functional MRI of the Brain, check out the animated video below.