Claire Sampson
AP Lang, McNamee
November 27, 2013
Research Paper Outline: Brain Structure and Personality
Argument: In today’s society we are constantly looking at personality and trying to manipulate
and change it to better ourselves. Historically, brain structure has been a promising avenue of
science, ever since the phrenologists. Scientists have now identified specific regions of the brain,
tagging them with precise personality traits. This, however, only provides an oversimplified and
cursory view of the anatomy of the brain in which correlations are considered causations, and
other more subtle physiologies are ignored.
1.) Introduction to personality:
Discuss briefly the different perspectives and approaches to looking at personality (psychology,
biology, sociology) and then introduce the 5 domains of personality but how lately the scientific
community has steered more towards studying the scientific basis.
a.) Define personality—

Different Perspectives
o Evolution of the views on neuroscience and the various approaches
to studying it—psychology, biochemistry, anatomy, etc.
(“Neuroscience: Breaking Down Scientific Barriers to the Study of
Brain and Mind”)

Common Psychological view
o Five domains of personality, belief in its “scientific” predictions
(“The Nature of Personality: Genes, Culture, and National
Character”)
o Shift from psychoanalysis and personality tests to studying of the
brain scientifically ("The Personality Problem.")
2.) Background/History:
This study of personality by looking at brain structure is not new and began as soon as people
viewed the complex anatomy of the human brain. Phrenologists identified specific loci for
personality (which actually has some validity), and later studies found specific brain damage that
could morph personality (Broca and Wernicke region for aphasia, Phineas Gage, lobotomy to
cure mental illness).
a.) Phrenology—

Original phrenologists and the origins of their studies, desire to figure out
how the mind works and what governs human life
o Phrenology maps they created, with each region having a specific
function (http://www.uh.edu/engines/phrenologicalchart.jpg)

Weighing brains of geniuses to see what creates “genius,” Einstein’s brain
had specific differences in it that many use to account for his extremely high
intelligence (“The cerebral cortex of Albert Einstein: a description
and preliminary analysis of unpublished photographs.")
b.) First discoveries of brain structure affecting personality/the brain—

Aphasia- loss of language and speech
o Broca and Wernicke regions- brain damage in a specific region can
affect speech in a specific and predictable manner (“Connectome”)

Phineas Gage and the first concept of brain structure being connected to
personality and temperament, large personality shift with little other effects
on the brain (“The Return of Phineas Gage: Clues About the Brain from the
Skull of a Famous Patient.")
o Other cases of trauma and brain damage affecting personality and
creating drastic changes (A different person': Personality change
often brain injury’s hidden toll.)

Lobotomy to “cure” mental illness (“How Lobotomies Work”)
o Original inception and why
o Discussion of structures of the brain and mental illness
3.) Common Conventions/Current Research:
The human brain has evolved greatly from other primates and mammals, allowing for specificity
in its anatomy and various lobes and regions that can create personality. Many personality tests
today rely on brain structure (R/L brain, top/bottom) and studies are finding correlations between
specific brain structure and personality traits, calling these changes in size or activation
manifestations of personality.
a.) “Purpose” and usage of each part or lobe of the brain—

How the human brain has evolved beyond that of other primates, size, brain
regions, etc. (“The Sociable Brain”)

The different lobes and regions of the brain and their roles that scientists
have found, specifically ones that directly affect personality (The Brain:
What’s Going On in There?)
o Chart/Image labeling each region with its role and function
b.) Personality tests based on brain sections—

Right/Left Brain, dichotomy
o There is some validity in the lateralization in terms of brain
function, but we do not use one side more than the other (“An
Evaluation of the Left-Brain vs. Right-Brain Hypothesis with
Resting State Functional Connectivity Magnetic Resonance
Imaging”)

Top Brain/Bottom Brain and cognitive functions ("How the Brain Creates
Personality: A New Theory.")
c.) Studies that correlate more specific brain structure and personality—

Size of brain regions
o Five domains of personality and corresponding brain structure,
correlation was found ("Brain structure corresponds to
personality," “Testing Predictions From Personality
Neuroscience: Brain Structure and the Big Five.”)
o Narcissistic personality disorder and cerebral cortex, correlation
between this disorder and a decrease in the part of the brain
concerned with empathy ("Altered brain structure in pathological
narcissism.")
o Accuracy of introspection and brain structure, correlation between
this trait and the brain anatomy (“Relating Introspective Accuracy
to Individual Differences in Brain Structure”)
o Gene that regulates brain size has been evolutionarily selected,
shows adaptation of the human brain and the importance of brain
size to human development (“Microcephalin, a Gene Regulating
Brain Size, Continues to Evolve Adaptively in Humans”)

Activation of certain brain regions
o Difference in introvert vs. extravert response in the amygdala,
using functional MRIs ("Scientists Seek Personality's Roots in
Brain.")
o Psychopath brains and irregularities in specific pathways and
structures that control empathy and emotions (Structural Brain
Abnormalities in Psychopaths—a Review)
4.) Critique/Other Views
Although studies of brain structure look promising, they rely too greatly on assumptions,
considering correlations to be causations and conclusions, when in reality they do not provide
enough information. There are other factors that govern personality, with many scientists now
relying on what they are calling the “connectome,” or epigenetics.
a.) Statistical Critique—
 Correlation is not a causation nor is it a conclusion (“Connectome”)
o Discuss the statistical reasoning

Studies are done post-mortem, which includes all life experiences that could
have changed the brain, hard to isolate specific causes or reasons
(“Connectome”)
b.) Factors that govern personality besides structure—

Neuronal Connections and the difficulty in finding definite boundaries
o Personality traits correlated to brain architecture and connections,
rather than specific regions (“Personality Is Reflected in the
Brain's Intrinsic Functional Architecture”)
o Experience spurs neurogenesis and resulting brain plasticity and
adaptation ultimately leading to individuality ("Emergence of
Individuality in Genetically Identical Mice")
 Evidence of adult neurogenesis (“What the Bomb Said
About the Brain”)

Environment
o Epigenetics- the effect of the environment on genetics ("Why Are
You and Your Brain Unique?” “Epigenetic Influence of the Social
Environment”)
o Neuroscientist who discovered that his brain had all the structural
hallmarks of a serial killer, while he lived a normal life and claims
his environment he grew up in is why (“A Neuroscientist Uncovers
A Dark Secret”)

Organs apart from the brain- other structural hallmarks, personality is not
merely in the structures of the brain
o Appearance and how personality is correlated to specific facial
features ("How your looks betray your personality")
o Correlation between personality and effects on the heart ("Cardiac
Signatures of Personality.")
5.) Conclusion/Social Views
Personality and where it comes from is a much debated and studied topic of neuroscience in
today’s society. We all want to know why we are who we are, and also how we can change it.
How can we become more empathetic, or extraverted, or altruistic?
a.) Defining and predicting personality
 Too hard to identify one cause, it is a combination
b.) Society’s desire to find the origin of personality and to morph personality ('The
Cult of Personality': Are You Normal? Think Again,” “Personality Theories: Critical
Perspectives”)