Published:

02/22/2011 12:43pm

Can you change your personality? Twin studies say no, brain studies say yes

"An unfortunate thing about this world is that the good habits are much easier to give up than the bad ones," said English short-story writer William Somerset Maugham.

The insight behind this quote is that deep-seated habits, or behavioral patterns, are difficult to change.

People's deep-seated habits reflect their personality, the clusters of dispositions, thoughts and feelings that make them unique. These pattern-forming features are also known as personality traits.

Personality traits can change gradually or through extensive counseling but they normally are relatively stable over time.

The thought that people can literally change their personality is controversial. The famous Minnesota twin family studies conducted by researchers at the University of Minnesota-Twin Cities, examined more than 8,000 pairs of twins to identify the degree to which personality is a result of nature or nurture.

Psychologist Thomas Bouchard found that monozygotic, or identical, twins reared apart were just as likely to have the same personality as twins who grew up together. Since twins who are reared apart are reared differently, the results seem to indicate that personality is primarily hereditary, just like eye color or height.

If personality traits are primarily hereditary, it might seem that people cannot change their personality.

However, there is room for change.

Just as childhood nutrition can make a small difference to a person's height, nurture can affect personality to some degree.

It is also possible that some of the qualities found between identical twins reared apart were due primarily to physical similarities. Two people who look the same, have similar voices, the same height, and so on are likely to get similar responses from others regardless of where they grow up. So, the environment may have played a greater role in shaping the twins' personality than the Minnesota twin studies showed.

Furthermore, the human brain is amazingly flexible. When people get a small stroke in the left prefrontal cortex, the regions around the damaged area can take over the functions the damaged area used to perform.

When the stroke is significant, the corresponding right side of the brain can take over the same functions.

Practice can make new neural connections!

If personality traits and behavioral patterns are at least partly grounded in the brain's neural networks, it should not come as a surprise that we really can change our personality and behavioral patterns.