Personality neuroscience: A new science of mind, or Phrenology 2.0? [Updated]

Psychologists who study the infinite variety of humans' personalities and temperaments often find themselves drawn to biological explanations of the personality traits that make us who we are. They surmise that factors such as heredity or brain structure must play key roles in whether we are outgoing or introverted, easygoing or prone to worry, callous or caring toward others.

But take that line of reasoning too far, and you get dangerously close to phrenology, a kind of science-cum-parlor game that was all the rage during much of the 19th century. The idea behind phrenology was that each of the mind's faculties lies at an exact and predictable spot in the brain, and that a person's propensities -- her tendency to embrace new challenges, his inclination to view others' motives suspiciously -- could be divined simply by observing the size and shape of his or her skull, which was thought to reflect the size and shape of the underlying faculties.

[Updated at 9:10 a.m.: An earlier version of this posting incorrectly identified phrenology as nephrology.]

This, of course, required complex maps of the head and specialists -- readers, if you will -- to guide the curious in discovery of themselves or others. It all looked very scientific -- and in some ways, helped give rise to the field we now know as neuroscience. But it came almost two centuries before the invention of imaging technologies capable of mapping the brain and watching it work. So the precise location of the mind's "faculties" was pretty much a shot in the dark.

But what if there was a germ of truth to the idea that personality traits do basically reside in predictable regions of the brain, and that the size or shape of those regions do reflect the fundamental makeup of a person's character? That is the intriguing preliminary finding of a study published this week in the journal Psychological Science. And it is the basis for a fledgling discipline called "personality neuroscience."

The "big five" personality traits -- extraversion, neuroticism, agreeableness, conscientiousness and openness or intellect -- are the dimensions of character that psychologists seem to agree make up each person's unique personality "fingerprint." Guided by neuroscience findings suggesting specific roles for certain brain regions, a team of researchers led by University of Minnesota psychologist Colin DeYoung measured the size of several regions in 116 healthy subjects' brains. They also had the subjects fill out standardized personality inventories, allowing them to locate each subject on the continuum of each of the "big five" traits.

For all but one of the "big five" -- openness, or intellect -- the researchers found that specific brain structures did vary in size in ways that tracked closely with a subject's score on one of the "big five" traits. If a subject scored highly on, say agreeableness, she was more likely to show greater heft in her brain's posterior cingulate cortex, which becomes active when a person exercises empathy. An extrovert was more likely to have a brawnier medial orbitofrontal cortex, a region known to be involved in responding to social reward.  

Unlike the phrenologists of the 19th century, DeYoung's team doesn't presume to know whether differences in the size of a brain region give rise to unique personality characteristics, or whether our personality differences cause our brains to develop in unique ways -- say, that when we practice random acts of kindness, our "agreeableness" center grows larger, or that a lifetime of social isolation might cause a region associated with "extraversion" to shrink.   

-- Melissa Healy

Comments

[mark Wilson]

you mean phrenology, not nephrology. Very funny mistake. I can't wait to show this to my nephrologist and see how good he is at reading head shapes.

[Dr. Spoctor]

I believe the author meant to write "phrenology," not "nephrology" (which is the study of the kidneys).

[Steve Silberman]

"Phrenology," rather.

[Brock Kirwan]

I think you mean 'phrenology' (the idea that you can tell something about one's mental abilities from the shape of the skull), not 'nephrology' (the study of the kidneys). Although both will tell you about the same amount about the brain.

[Robert Hamersley]

Nephrology is the branch of medicine dealing with the kidneys. I believe you must mean Phrenology, the divining of personality traits from irregularities in skull shape.

[aneesh]

spelling mistake... u mean phrenology not nephrology

[Jane]

Hey LA Times,

Those who treat kidney disorders (nephrology) don't have much to do with deciphering personalities. You mean "phrenologists," surely. Don't you....?

[Buck]

I think you might mean Phrenology, not nephrology which is the study of the renal system and kidneys.

Your article would have more weight if you use the correct terminology.

[Colleen Davis]

Interesting piece, but each instance of 'nephrology' should be corrected to 'phrenology'.

[Lesle]

I believe you mean, phrenology, not nephrology here....

[EG Haid]

Ooops! Nephrology is the study of the kidney and its diseases. You mean phrenology (as you say later). The tendency to transpose syllables is called malapropitis and is located in the brain's left parietal area...

[Leticia]

PHRENOLOGY (not nephrology). You need a good copy editor.

[McKenzie Miller]

I believe you confuse the terms "nephrology" and "phrenology"-- nephrology is the study of kidneys while phrenology is the term you seek, describing the study of personality traits and skull shape.

[Robin]

I think you mean "phrenology", not "nephrology".