June 22nd, 2010
05:58 PM ET

Personality shows up in brain structure

By Elizabeth Landau
CNN.com Health Writer/Producer

Some people are more outgoing than shy, or worrisome than carefree. Such personality differences are now being explored biologically in the brain.

A new study in the journal Psychological Science finds that several personality traits are associated with definite brain regions. Scientists from the University of Minnesota, University of Toronto, Yale University, and The Mind Research Network in Albuquerque, New Mexico, collaborated on the study.

Participants were 116 people, half of whom were male, and all between 18 and 40 years old. They were given a personality test and then underwent magnetic resonance imaging.

The researchers found evidence in the brain for four of the "Big Five personality traits": extroversion,
neuroticism, agreeableness, and conscientiousness. They looked at the volumes of various brain regions to see how greater or smaller volumes might be connected to personality traits. But they did not find clear associations for the fifth trait: openness/intellect.

A brain region involved in processing reward information, called the medial orbitofrontal cortex, seemed to be associated with how extroverted participants were. Extroverted people tend to be more sociable and talkative.

Brain regions associated with threat, punishment, and negative affect seemed to have something to do with how neurotic participants were. Neuroticism includes elements of irritability, anxiety, and being self-conscious.

Brain areas dealing with information about the intentions and mental states of other people were associated with agreeableness. Cooperation, compassion and politeness are part of agreeableness.

The lateral prefrontal cortex, involved in planning and the voluntary control of behavior, seemed to be associated with conscientiousness. People who are highly conscientious tend to be self-disciplined and orderly, rather than impulsive.

The one major personality trait that did not have an association with a brain area volume in this study was openness/intellect, which includes people who are creative, philosophical, imaginative, and intellectually engaged. This is also the only trait that has been associated with intelligence in previous research. Further study would be needed to determine how biology might be related to this trait.

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soundoff (371 Responses)
  1. Michael

    Perhaps this is a chicken-and-egg issue. Let's turn it on its head. Maybe brain structure does not drive personality, but rather personality drives brain structure? As working out increases the volume of specific muscles, exercising certain behaviors increases the volume of certain brain regions. Constantly acting extroverted leads to increased volume in the medial orbitofrontal cortex, for example.

    June 22, 2010 at 19:18 | Report abuse | Reply
  2. TC in Al

    Can this type of imaging comparison lead to better understanding of pre installed instincts and brain contents ? It might be possible to prove babies minds get programmed by their mother's brain during gestation, transferring memories, knowledge, personality, possibly past life experiences, etc..., not only the structures of the brain, or pattern of neurons, but the actual sensory data stored in the brain as well !
    People would assume we'd remember past life memories as separate from our own, yet even now, in our most conscious state, we'll record our life sensory experiences for an avg 16 hours nonstop, then sleep for 8 hours, as we dream, several memories are reactivated and rearranged, "key frames" from that day, or associations triggered in that day, could gain stronger presence in the subliminal mind, however, if you woke and spent the next 16 hours trying to recall every detail of the previous waking 16 hours, It'd take about a minute or two, before you'd remembered all you could verbatim, from those previous 16 hours, so...

    June 22, 2010 at 19:29 | Report abuse | Reply
  3. kim

    I'm sure the researchers are aware of the plasticity of brain development. Brain development is influenced by how a person uses their brain. Let's not confuse cause and effect; all we have in this article is a correlation.

    More important: patterns that are meaningful in comparisons of groups of people should not be applied to individuals. Don't make this the new phrenology, in which proclivities of individuals were diagnosed from bumps and bulges.

    June 22, 2010 at 20:21 | Report abuse | Reply
  4. Nitrogen

    The age of prolonged job-applicant surveys is almost over. "Put your head in this hole and we'll call you if your medial orbitofrontal cortex is of sufficient size."

    June 22, 2010 at 21:03 | Report abuse | Reply
  5. Marcio da Cruz Alves

    Dear Elizabeth Landau.
    Thank you very much for this article. I teach at the Florida Christian University (Orlando, FL) where we are truly interested in this matter. Please, could you let me know how can I get the original text of this study?
    Best regards.
    Marcio Cruz.

    June 22, 2010 at 21:28 | Report abuse | Reply
  6. elle

    I believe this is all based on the research of the controversial but pioneering psychologist, Eysenck. This from the Web:

    The PEN model, proposed and advocated by Eysenck as the overarching paradigm of personality psychology, has two main aspects: descriptive and causal. The descriptive aspect of the model is a hierarchical taxonomy based on factor analysis. At the top of the hierarchy are the superfactors of Psychoticism, Extraversion, and Neuroticism (PEN). These superfactors are comprised of factor analyses of lower-order factors such as sociability and positive affect (components of Extraversion). These factors are comprised of factor analyses of low-order habits such as liking to study with a group of people (a component of sociability). These habits are comprised of factor analyses of lower-order behaviors such as studying for the personality midterm with a group of people..."

    He worked out a system in which certain scores, and combinations of scores on the various traits correlate to behaviors pretty strongly. His original research has been watered down and is used in business (4-quadrant) but the real thing is far more interesting, and well supported.

    When tested for example, a person who scores high on neuroticism and low on the other indicators would not much enjoy being in large crowds; would tend to be a worrier, risk-averse, detail-oriented - not many surprises here.

    But the combinations are where it gets fascinating: somebody who scores high on neuroticism (N) and high on extraversion (E) would tend to love attention and being in the spotlight; would dress meticulously and for effect; might be fussy and self-centered, cares about image a lot; might own their own small business.

    People who are high on psychoticism, high on neuroticism and low on extraversion (PNE-) tend to be great "second-in-commands" to leaders and entrepreneurs, because they are both vicarious and detail-oritented, as well as risk-averse - yet they like being close to leaders and can be in command, as long as they are linked to somebody higher because they have that worrying trait. Good bean counters.Good PR flacks.

    People high on psychoticism and high on extraversion but neutral on neuroticism (PE) tend to be like Bill Clinton: sexually aggressive and bold leaders, with short tempers. They are also entrepreneurs, as are people high on P and neutral on E and N - CEOs. Taking risks doesn't bother tham, They can be ruthless, short tempered, impatient, bossy, aggressive.

    People high on all three (PENs), are overrepresented in prison populations and are often in trouble, blame others for their woes, lie a lot, take big risks for fun, easily bored and don't much care about consequences. Not nice people.

    People who are high on neuroticism, low on extraversion and neutral on psychoticism (NE-) are introverts and often recluses. Might prefer a career like librarian. Dislike risk, don't trust people much.

    People who are pure "E's" - cheerleader types, fulll of enthusiasm and energy but not much drive or future planning. Fun loving, not worriers, short attention spans..

    It's fun to read about this and test yourself and friends. Me? A pure "N".

    June 22, 2010 at 23:05 | Report abuse | Reply
  7. Mischa

    Interesting that none of the usual suspects, one million times ten, comment on this article. Speaks volumes.

    June 22, 2010 at 23:15 | Report abuse | Reply
  8. B.

    This raises an interesting question: To what degree does our experience determine the shape of our brain or the shape of our brain determine how we relate to our experience?

    June 22, 2010 at 23:28 | Report abuse | Reply
  9. Toshi O.

    Awesome findings, but now what?

    It's cool if this were enough, but can we change it?
    If my mood changes over time will the graphs be affected?

    It seems to me as thought this is a step in the right direction, but plenty more to be uncovered.

    Toshi O.

    June 22, 2010 at 23:42 | Report abuse | Reply
  10. Jackie

    As with any evaluation, they are just snapshots of one particular point in time. Brain energy and activity are both subject to change and dependent upon mood, previous night's sleep, hydration, and inumerable other variables. I think we should be very careful in analyzing brain function and assuming it is a constant. I also think that free will/judgment and intelligence play large parts in our day to day decision making. However, in the same breath, MRIs definitely show activity within particular parts of the brain. I compare it to a "genetic marker" or a "family trait" and the fact that everyone has the capacity to forge their own unique paths and form their own habits.

    June 23, 2010 at 00:40 | Report abuse | Reply
  11. Joe

    Interesting stuff. You have to be careful with fMRI studies... they can only say so much. But conjoined twins are clear examples of how there is at least some "nature" component of personality.

    June 23, 2010 at 00:40 | Report abuse | Reply
  12. AnProf

    Well, of course if neurons in one area were being used more, for worrying or etc. then clearly there would be more synapse connections and grey matter in that region.
    This study should not be mis-interpreted that the brain is CAUSING the personality differences.

    June 23, 2010 at 00:49 | Report abuse | Reply
  13. DRFOX

    Some genetics, but the regions develop based on our experiences in life. MOST of us can make changes in our lives. I believe MOST of us are created equal. It is the choices that matter, not the genetics.

    June 23, 2010 at 01:09 | Report abuse | Reply
  14. Peter E

    Before people start to draw conclusions: there is nothing in this article about whether these brain biologies are developmental or genetical in origin. Although I'm sure there will be enough people cracking lame jokes connecting this article with completely unrelated, perhaps even insulting or racist myths.

    June 23, 2010 at 01:32 | Report abuse | Reply
  15. Limbaugh is a liberal

    This study is biased! It doesn't represent the entire population! What about journalists, tv personalities, commentators, and other media type, you know, people who don't have any brains? Oh wait... I think I just found the indicator of the sixth personality trait, journalism.

    June 23, 2010 at 01:37 | Report abuse | Reply
  16. dan

    I look at stories like this in total amazement.
    how wonderful research and doctors have time to spend on this.

    No the real amazement is if you ever have grand mal seizures.

    You will be given an mri and eeg.

    If both turn out normal you will be told take this drug and if you will not take this drug do not come back until you will take this drug.

    The point is the doctors do not investigate to find the cause.
    The doctors explanation is it could be 100 things causing the seizures
    and that is just too complicated of a problem to solve.

    What about looking for seizures showing up in brain structure instead of personality traits?

    June 23, 2010 at 01:54 | Report abuse | Reply
  17. Susan from San Antonio

    Interesting findings. There are millions of ways in which these parts of the brain inter-relate, meaning that actual behavior is not in the least predictable. Extroverts can be cowed into introverted behavior. Personalities can be squashed by mental cruelty. Behavior therapy could not possibly restore the alternative routes the brain has taken in order for the human to survive. So, the finding is significant. Why?

    June 23, 2010 at 05:55 | Report abuse | Reply
  18. J Twedt

    If they would simply go by the MBTI or Keirsey Temperament Sorter, they would find what they are looking for. The "Big Five" is basically a test that says that if you aren't an ENFP (according to the previous two tests) you're an ass. The both the MBTI and KTS use four basic pairs.

    June 23, 2010 at 05:56 | Report abuse | Reply
  19. Susie

    I find this sort of research fascinating. There is already a best selling book, written by Dr. Amen, on the subject for the average reader who wants to learn more. He has a whole bunch of books based on having studied the brain with SPECT scans. Personally, I try to get my "brain food" omega-3s everyday and so do my grandkids since they have plenty of Gudernoobs made by WooHoo Foods.

    June 23, 2010 at 06:20 | Report abuse | Reply
  20. janeann fessler

    Since I was a child I have wondered if personality was the reflection of the soul. According to this article, there is evident that might suggest personality may have a biological basis.nIt might explain why babies seem to be born with a personality from birth.

    June 23, 2010 at 06:27 | Report abuse | Reply
  21. M

    Great....Now potential employers will begin asking applicants to submit to brain scans.........

    June 23, 2010 at 07:11 | Report abuse | Reply
  22. Timothy Lee

    Interesting! It makes one wonder if – one day – science will be able to improve the human mind (making us less prone to criminal behavior) while not loosing our essential humanity. I am sure that people will try it some day. I know that this will generate allot of fear about scientists playing god. Then again, the real god isn't doing such a good job so maybe we should give scientists a turn.

    June 23, 2010 at 07:28 | Report abuse | Reply
  23. bo peep

    What this article doesn't say is to what extent these traits and their associated brain structures are genetically determined. In other words, does the brain structure determine the trait or does the brain structure develop in response to the predominance of certain personality traits?

    June 23, 2010 at 07:29 | Report abuse | Reply
  24. atapcreations

    Perhaps some sort of stimulation of certain brain structures will lead to personality enhancement therapies.

    June 23, 2010 at 07:33 | Report abuse | Reply
  25. dave

    In the future your employer will now want a MRI of your brain, DNA chart and family tree, voice recording, and of coarse the most important little diddy of information your Facebook account.

    June 23, 2010 at 08:23 | Report abuse | Reply
  26. NinaCarmen

    This is quite interesting; however, I would greatly appreciate appropriate references in the article, since I would love to read the original research in the Psychological Science journal. What is the title of the original article, please?

    Thank you, and be well.

    June 23, 2010 at 08:27 | Report abuse | Reply
  27. Joan Burkholder

    Not a comment; more questions. Do these traits show up at or soon after birth? Can various aspects of these traits be influenced by socializing by parents and life experiences outside the home as the personality matures? Does the diet affect the developement of the various personality types? This research seems to be just the beginning and much more work needs to be done. Very exciting.

    June 23, 2010 at 08:31 | Report abuse | Reply
  28. justsomeperson

    All my life I've tried to change my personality. Certain things I could change a little, but the tendency to be introverted seems impossible to shake and has been the bane of my existence. Maybe this explains it. Or maybe not.

    June 23, 2010 at 08:37 | Report abuse | Reply
  29. Wzrd1

    Cute study. Let us know when it is done with a large enough group to arrive at REAL trends.
    A study of 116 participants is only an initial investigation.
    1160 participants would be newsworthy. 116 is pseudo-science.

    June 23, 2010 at 08:47 | Report abuse | Reply
  30. Jorge

    I would love to volunteer for this experiment, but without taking the personality test first. I'll like to know how much they can tell about my personality without any biases.

    June 23, 2010 at 08:56 | Report abuse | Reply
  31. S. Posey

    The results of this study are not terribly suprising – it makes sense that brain structure affects personality. Other studies have suggested this for years. I look forward to larger studies. I wonder how the structure of the adult brain is affected by childhood experiences. The growing brain is plastic, always making new connections and pruning connections no longer needed, so the question of nature vs. nurture is always there. And the adult brain may not be as static in structure as we were taught in school.

    It is my hope that science will in the near future make discoveries about the brain that can improve the treatment of mental illness and the way we raise and educate our children, to improve all our lives.

    June 23, 2010 at 09:00 | Report abuse | Reply
  32. HilaryC

    What would they do with this information? I think it's really interesting and everything, but does this mean that maybe someday scientists and doctors will be able to tell new parents that their child will grow up to be a neurotic, self-indulged, heartless person? I mean, who wants their kid to grow up to be that? And what would they do to prevent it?

    June 23, 2010 at 09:04 | Report abuse | Reply
  33. rk

    So now the question becomes – do these behaviors/traits shape the brain, or is it the other way around?

    June 23, 2010 at 09:05 | Report abuse | Reply
  34. Jeff

    So the phrenologists were right after all; they just should have looked a little deeper.

    June 23, 2010 at 09:09 | Report abuse | Reply
  35. John

    A couple of thoughts:
    (1) 116 people is extraordinarily few for a study that is trying to show us that brain regions are 'connected with' personality traits

    (2) Given everything we know about the brain, correlating *size* of certain regions with personality traits seems like a pretty unsophisticated explanation.(It's like saying 'the smartest person has the biggest brain because they have the most neurons") Isn't there some underlying structure changes in which can explain personality differences?

    (3) How did they assess the subjects for personality traits? Did the subjects self-report? Notoriously, people misjudge the sorts of characters they are.

    (4) Who decided on the 'Big Five' traits? Is the assumption that all the other traits are built out of these? Personality is a complex business: it is unlikely the big 5 can explain everybody's differences...

    June 23, 2010 at 09:20 | Report abuse | Reply
  36. Mark Johnson

    As I understand it, the brain develops and changes physically over the lifespan, in part in response to environmental stimuli. One might take from the description in the news piece that differences in brain structure cause differences in personality. However, might it be possible that personality is created from the environment (e.g., nurture over nature) and that the observed biological differences are simply a by product of this. Is there evidence to refute the hypothesis that personality causes differential brain development and not the other way around?

    June 23, 2010 at 09:25 | Report abuse | Reply
  37. Goose66

    Does that mean we all must live with our personality traits (good or bad) or does the research further shed light on ways to alter the brain structure/activity to "normalize" one's personality? I am all for diversity, but it would be nice to be less neurotic at times.

    June 23, 2010 at 09:47 | Report abuse | Reply
  38. Linda McIsaac, Ph.D.

    We are open to working with others using our online tool that is statistically Reliable and Valid and highly predictive. Contact: Linda McIsaac 608 327-1000

    June 23, 2010 at 09:57 | Report abuse | Reply
  39. LouAz

    116 test items for five variables ? Sounds like a funded study that was going to get five answesr no matter what the data showed. Specks in flysh#t.

    June 23, 2010 at 09:57 | Report abuse | Reply
  40. Matt

    Im sorry; this is Nazi-istic. What-since the 40's we've gone from measuring the skulls of different people to determine intellect and "traits" to THIS?

    What "good" can this be used for? Are people cattle, now?

    June 23, 2010 at 10:31 | Report abuse | Reply
  41. Megan

    You left out Openness from the Big 5! You can remember it from the pneumonic OCEAN (Openness, Concientiousness, Extroversion, Agreeableness, Neuroticism).

    June 23, 2010 at 10:36 | Report abuse | Reply
  42. Megan

    Just kidding, I re-read it and realized what you were saying. . . Still, that pneumonic was helpful, huh?

    June 23, 2010 at 10:37 | Report abuse | Reply
  43. Steve

    @Michael If what you say is true then all human brains would be basically identical at birth with respect to these structures. I am not sure if that is true.

    June 23, 2010 at 12:13 | Report abuse | Reply
  44. TMH

    Michael – how about if there is no chicken and egg situation but rather the two are intertwined in such a way that they both influence each other?

    June 23, 2010 at 12:16 | Report abuse | Reply
  45. Skeptic420

    What if brains don't exist and this is all an illusion?

    June 23, 2010 at 12:33 | Report abuse | Reply
  46. Bill

    Can a person have all "Big Five personality traits" hard to figure out where on fits?

    June 23, 2010 at 12:36 | Report abuse | Reply
  47. Prof. K

    Thisstudy is a reductist approach to study the human behavior. The study assumes that the similar behaviors have the similar undrlying correlates in the brain but I think it is a gross approximation which may as well be a mistake. The human behavior is very complex and depends upon nature, nutrure and the interaction of the nature with nuture. In other words

    Human Behavior = Nature(DNA, RNA) + Nurture (Enivronment, upbringing, love, understanding, knowledge) + Free will that determines how nature interacts with nurture

    In most of the cases, the second two factors (nurture & free will) can have bigger contributions to behavior than the nature(RNA and DNA). In summary, every human has the intrinsic ability to empower his/her DNA with good nurture and by interpreting the environment in accord with the known truths.

    At the present time we only know the summary charcateristcs of the brain and lack the molecular and submolecular understanding but one can not deny the role of both the DNA & environment on the emergent human behavior.

    June 23, 2010 at 13:56 | Report abuse | Reply
  48. Mike

    Franz Josef Gall proposed 200 years ago that different personalities had enlargement in different parts of the brain. His ideas have been ridiculed-but it seems he was onto something.

    June 23, 2010 at 14:28 | Report abuse | Reply
  49. jeannieb

    All this makes me remember the Tom Cruise movie "Minority Report". Isn't that the one where he is enabled to know if someone wil at some future date be guilty of a crime?

    June 23, 2010 at 14:57 | Report abuse | Reply
  50. Jonathan Weiss

    Absolutely idiotic pseudo science. This approach was refuted by Hegel in the Phenomenology. What a waste of money that should be spend on real reasearch.

    June 23, 2010 at 15:23 | Report abuse | Reply
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