Scientists in the UK say they've found a strong correlation between a particular set of connections in the brain and a person's likelihood of displaying positive lifestyle and behaviour traits. 

Brain scans revealed that positive traits such as vocabulary, memory, life satisfaction, income, and years of education were linked to higher connectivity in certain areas of the brain, while negative traits, such as anger, rule-breaking, substance use, and poor sleep quality, were linked to lower connectivity. 

"We've tried to see how we can relate what we see in the brain to the behavioural skills we can measure in different people," lead author Stephen Smith from Oxford University's Centre for Functional MRI of the Brain told Steve Connor at The Independent. "In doing this, we hope to able to understand what goes on 'under the bonnet' of the brain."

Smith's team worked with data from the Human Connectome Project (HCP) - a US$40 million brain imaging study of 1,200 people launched in 2010, one of the goals of which is to identify the networks that are active when the brain is idle, which "are thought to keep the different parts of the brain connected in case they need to perform a task," says Sara Reardon at Nature Magazine.

The HCP has so far released data from 461 of those subjects, aged between 22 and 35 years old, and Smith and his team analysed the connections in their brains, then compared these to 280 behavioural and demographic measures, such as age, personality traits, history of drug use, socioeconomic status, and performance on several intelligence tests.

"The quality of the imaging data is really unprecedented," said Smith in a press release. "Not only is the number of subjects we get to study large, but the spatial and temporal resolution of the fMRI data is way ahead of previous large datasets."

Publishing in Nature Neuroscience, Smith and his colleagues describe how they mapped the processes in each participant's brain to come up with personalised 'connectomes'. These connectomes mark the connections between neurons in 200 separate regions in the brain and measure how effectively they communicate between each other and where the strongest connections lie, based on the amount of nerve signalling going on.

"You can think of it as a population-average map of 200 regions across the brain that are functionally distinct from each other," says Smith. "Then, we looked at how much all of those regions communicated with each other, in every participant."

Next, the researchers took 280 different behavioural and demographic measures for each subject and performed a 'canonical correlation analysis' for the two data sets. This basically means they used a lot of complex maths and computer models to identify relationships between two large sets of complex variables.

"The team was surprised to find a single, stark difference in the way brains were connected," Reardan reports for Nature. "People with more 'positive' variables, such as more education, better physical endurance and above-average performance on memory tests, shared the same patterns. Their brains seemed to be more strongly connected than those of people with 'negative' traits such as smoking, aggressive behaviour or a family history of alcohol abuse."

While it's not yet clear if these correlations are truly reflective of a physical connection between personality and behaviour traits and physical characteristics of the brain, but in identifying them, the researchers could help future efforts to confirm or discount this possibility.

"It may be that with hundreds of different brain circuits, the tests that are used to measure cognitive ability actually make use of different sets of overlapping circuits," says Smith. "We hope that by looking at brain imaging data we'll be able to relate connections in the brain to the specific measures, and work out what these kinds of test actually require the brain to do."