A Psychobiological Framework for Personality Neuroscience
The topic of my research is the structure
and sources of human personality. By "structure," I mean primarily the basic
elements or traits that make up personality. Psychometric research has demonstrated that five broad domains
(the "Big Five") can be used to organize most aspects of
Neuroticism (negative emotion, anxiety, vulnerability, irritability)
empathy, cooperation, politeness)
Conscientiousness (organization, industriousness, diligence, constraint)
Extraversion (positive emotion, enthusiasm, sociability, assertiveness)
Openness/Intellect (imagination, intelligence, curiosity, creativity)
Theoretically, most stable observable individual differences in cognition, emotion, motivation, and
behavior fall into one of these five domains or can be
described in terms of a combination of two or more of them.
How do individual differences in brain function produce individual differences in personality? The Big
Five model has great potential for integrating the vast amount of
existing research on individual differences and for organizing the
emerging field of personality neuroscience. Personality measures
generate a large collection of intercorrelated trait variables; the
brain is a large collection of interacting neural systems. My long-term
goal is to map traits onto their sources in the ongoing functioning of
the brain, using techniques including neuroimaging and molecular genetics.
Additionally, I am working on a theory
that not only specifies the psychological and biological
functions underlying personality traits but also describes them
as integrated and interacting elements of an adaptive system.
Current Research Projects
1. A Hierarchical Model of Personality Based on the Big Five
Personality traits can be categorized by arranging them into a hierarchy, based on
their correlations with each other. Broad domains (e.g., Extraversion), each encompassing
many related traits, are located near the top of the hierarchy, and very
specific patterns of behavior and experience (e.g., talking a lot) are located near
the bottom. More
specific traits that group together within a more general trait are
assumed to share underlying sources that are reflected by the more
general trait (though the fact that they are differentiated at the more
specific level implies that they do not share all of their sources). I
have been working to identify both higher- and lower-level traits in
the hierarchy, relative to the Big Five. The resulting organization is depicted here. [Related publictions]
Factors of the Big Five: Stability and Plasticity
The Big Five
were originally thought to be the most general level of
personality description. However, they proved to be consistently
related to each other in a way that indicates two higher-order factors
or metatraits. The first of these combines Emotional Stability (the
opposite of Neuroticism), Agreeableness, and Conscientiousness. The
second combines Extraversion and Openness/Intellect. We
have interpreted the first of these as a broad Stability factor and the
second as a Plasticity or exploration factor.
Stability and Plasticity
represent the manifestation in personality of the two broadest
requirements of any human being: 1. the need to maintain a stable
psychosocial organization to achieve various goals, and 2. the need
to incorporate novel information into that organization, as the
situation of the individual changes both internally and externally. The
primacy of these needs reflects the one universal problem of all living
things, namely uncertainty – unpredictable change, novelty,
the unexpected, the unknown; it is this problem that
renders stability a
challenge and plasticity advantageous. Similar concepts of stability
and plasticity can be usefully applied to understanding phenomena as
varied as societies and neurons, but I am most interested in their
particular manifestation in personality. We
have hypothesized that Stability is linked to the neurotransmitter
serotonin and that Plasticity is linked to dopamine.
Between Facets and Domains: Ten Aspects of the Big Five
A behavior-genetic study has demonstrated
that two genetically-based factors underlie the shared variance of the
six facet scales that make up each of the Big Five personality
domains in the popular NEO Personality Inventory – Revised (Jang,
Livesley, Angleitner, Riemann, & Vernon, 2002). We have found similar factors in analyses of even larger numbers of facets.
These findings indicate the presence of two distinct (but correlated)
factors, or aspects, within each Big Five domain, representing an
intermediate level of personality structure between facets and domains.
We have constructed a 100-item measure of these ten aspects of the Big
Five, called the Big Five Aspect Scales (BFAS), which has
been validated in two large samples. The BFAS provides a measure
of the Big Five, each broken down into two aspects,
which are more
parsimonious than the facets but more specific than the domains, and
which appear to have distinct genetic substrates. We
are optimistic about its potential utility for personality
neuroscience. The BFAS is in the public domain. Please use it! [Formatted versions of the BFAS for self ratings and for peer ratings]
2. Openness/Intellect and Cognitive Abilities
I am attempting to develop a neuropsychological model of the trait of Openness/Intellect. I am interested in a variety of
higher cognitive functions that fall within the purview of Openness/Intellect
(such as intelligence, insight, reasoning, divergent thinking, working memory, and learning) and
that allow individuals to be cognitively flexible and creative.
Externalizing behavior covers a range of often problematic behaviors,
including impulsivity, aggression, hyperactivity, antisocial
behavior, and drug abuse. I am interested in how externalizing behavior relates
to individual differences in
personality and cognition and their underlying biological substrates.
In other words, what are the sources of externalizing behavior and its
related processes? Externalizing appears to have a complex set of influences involving both increased impulses and reduced top down control. We found that externalizing behavior is related to low Stability and high Plasticity, plus low intelligence.
Past Research Projects
Types and Processes of Self-Deception
I have been involved in research carried out by my graduate advisor, Jordan Peterson,
on individual differences in self-deception.
We conceive of self-deception as failure to explore subjective evidence
plans or beliefs are in error. I have been particularly interested
in the difference between the two types of self-deception
found in factor analyses of questionnaires designed to measure bias.
The first type is overconfidence or egoism, the second is conformity or
moralism. It appears that these seemingly very different traits share
something important, namely a rigid devotion to one's current plans and
beliefs, regardless of whether these stem from within (egoism) or from
an external moral system (conformity).
Individual Differences in Responses to Information Technology
In the information age, computers and the internet are
increasingly part of our everyday lives, but they also constitute an
extremely complex technological system that must be mastered by a
species that certainly didn’t evolve in the company of computers.
interested generally in the ways in which people respond to novel
complexity of any kind. I am interested specifically in whether
differences in responses to information technology have any effect on
psychological assessment, which increasingly takes place on computers.
With Ian Spence, I have developed a new instrument, the Technology
Profile Inventory (TPI), to measure a wide range of attitudes
toward information technology. Contact me
or Ian Spence if you would
like a copy of the most up to date version of the TPI.
[Back to Homepage ... Back to Top]