A 50-Plus-Year Perspective on Personality Theory

The term “personality” has been defined in different ways, but here we will define it to mean the study of individual differences. Why do people differ from one another? Why do people behave differently in different situations and at other times of their life?

Personality is taught today pretty much as it was 50+ years ago.

After describing two problems responsible for this situation, I provide two ways forward and consider four remarkable contributions that this way forward has provided.

Two Problems

Problem 1: When I arrived at Fordham University in 1970 as a newly minted Assistant Professor, I was scheduled to teach Theories of Personality to graduate students enrolled in the clinical psychology doctoral program.

I knew I did not want to continue with the approach taken in my undergraduate and graduate Theories of Personality courses. Personality textbooks reviewed and continue to review positions taken by classic theorists such as Freud, Jung, Adler, Skinner, etc.

The first problem with this approach is that while informative and generally educational, it has yielded minimal if any scientific progress over the past 50+ years. The main reason for this problem is that at least five core unresolved philosophical disputes underlie and explain why these theorists have their varied positions.

Rychlak (1968) discussed these and related philosophical schisms in detail. I based my graduate course on this text so that my students could better understand why the major personality theories differed in irreconcilable ways and, therefore, why they would never be able to compromise and move forward.

Science typically does not resolve philosophical schisms, which explains why theories of personality are still largely taught today in the same way that they were 50+ years ago with textbooks that strongly resemble the ones that I used as an undergraduate and graduate student.

Problem 2: The second devastating problem is that the scientific study of personality has largely been correlational. While correlation is a prerequisite for causation, it alone is never proof of causation which requires experimentation and involves manipulation. The so-called “famous personality experiments” have all raised ethical questions. Alternatives are required.

Two Ways Forward

The first way forward involves basing personality on the study of learning and memory because all psychological phenomenon depends upon them. If infants could not learn, they would not develop into the children and adults with personalities with which we are familiar. That dementia destroys memory, learning, and personality is further proof that learning and memory are fundamental to personality. A learning mechanism is central to any personality theory that aims to explain long-term attitude development and change.

The second way forward concerns an exception to the claim made above that science cannot resolve philosophical schisms. I refer to the mind-body problem I addressed in “The Missing Link.”

The ability to simulate learning and memory with artificial connectionist neural network models effectively solves/resolves what has long appeared to be a mind-body problem. That post shows that synapses are the missing link between psychology and biology. Memory can form as a result of Hebb’s rule, which states that “neurons that fire together wire together.”

This process entails the biological mechanisms of experience-dependent plasticity that strengthen the synapses that connect neurons that fire together and drive learning via memory formation, as I discussed in “Understanding How Reinforcement Works.” The connection modification perspective presented there is also basic to understanding how machine intelligence works. I addressed this topic in “Belated Happy Birthday Alpha Zero.”

Four Remarkable Contributions

Four remarkable contributions have followed from the above-mentioned way forward. The first remarkable contribution is that virtual personality models (VPMs) have been constructed based on this new learning and memory science that are completely open to experimentation (e.g., Read & Miller, 2002; Read et al., 2010).

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Every aspect of their construction, developmental history, and situations in which they find themselves is entirely under the experimenter's control. These experiments are completely replicable across investigators who share computer code. They produce true biopsychological and psychobiological models with causation running in both directions.

The second remarkable contribution is that the mechanics of these VPMs clearly establish the importance of unconscious processing to personality theory. The neural network processing that defines and characterizes VPMs begins prior to awareness. Consciousness can be understood to emerge from this processing. Theories that assume consciousness, as all classic personality theories do, cannot explain consciousness because we reason from assumptions, not to them.

The third remarkable contribution is that these VPMs demonstrate the relevance of parallel constraint satisfaction as the primary psychological basis of social cognition. The following four classic cognitive dissonance experiments can be explained based on parallel constraint satisfaction: Free Choice, Forbidden Toy, Forced Compliance, and Severity of Initiation (Read & Simon, 2011; Read & Monroe, 2019).

The fourth remarkable contribution concerns the synthesis of the personality dynamics vs. structure schism that has characterized personality theory from its inception. While Freud discussed personality structure in terms of Id, Ego, and Super Ego, he and his followers placed far greater emphasis on the psychodynamics among these structures, including ego defense mechanisms.

Alternatively, contemporary theorists used the statistical technique of factor analysis to quantify and characterize adult personality resulting in the Five-Factor Model. These two approaches have divided theorists and investigators for decades. The Read et al. (2010) VPM model uses a motivational system that governs approach and another motivational system that governs avoidance. Traits are modeled by varying the sensitivities of these systems. This leads to an understanding of personality structure and dynamics in terms of structured motivational systems.

Network Principles

Scientific explanations are based on empirically supported principles. Empirically supported core and corollary network principles were introduced by Tryon (2012) and expanded upon by Tryon (2014) as a basis for cognitive neuroscience and psychotherapy.