What Is Parsimony in Psychology?

Karen Doll, Author
Updated on November 24, 2021

Parsimony is all about simplicity. According to the law of parsimony, we should always use the simplest approach, rather than try to use complicated explanations. It requires focusing on the most impactful and effective evidence and data, without considering extraneous factors.

parsimony psychology

Parsimony psychology could be for you if you are looking for a simple, efficient, and applicable way to address mental health issues. Often, people who seek out psychological help find the unnecessary complexity overwhelming. This added to other mental health symptoms, can make people feel hopeless, especially if there aren’t tangible and pragmatic explanations or treatments for their experiences. Focusing on explanations and theories that are practical, with clear conclusions, can be a useful way to address mental health issues.

Defining Parsimony

The term “parsimony” was derived from the Latin word parser, meaning to be sparing. The general meaning of the word is excessive thriftiness or frugality. In some contexts, this has a negative connotation, suggesting a lack of generosity or miserliness. However, there is also value in the concept of parsimony. Parsimony in psychology entails identifying the simplest and most accurate explanation for brain processes and human behaviors

The law of parsimony suggests identifying the simplest, least complicated explanation of a situation or observation. Even philosopher Aristotle supported this method, saying “the more limited, if accurate, is always preferable.”

The law of parsimony is often referred to as Occam’s razor. It was named after theologian William of Ockham in the 1300s, who authored the term “numquam ponenda est pluralitas sine necessitate.” This means “Plurality must never be posited without necessity.”

Years later, scientist Sir William Hamilton named the phrase “Occam’s razor” to describe the process of “shaving away” unnecessary or peripheral assumptions in logical reasoning. Subsequently, scientists in varying fields adopted this practice in their own studies. It involves using the fewest steps, with minimal resources, leading to the optimal conclusion.[1]

Benefits of Applying Parsimony in Psychology

Brain function is complex and much of it remains a mystery. While scientists are committed to simplifying the study of psychology and human behavior, there is still a gap of understanding. Parsimony can make psychology less abstract and more tangible. A good therapist or mental health professional can use this framework to provide accurate and valid explanations that are relatable and easy to understand.

Parsimony psychology ensures that explanations are simple, helpful, and do not rely on unsupported assumptions. It also relies on tangible observations and proven data with replicable results. Parsimonious descriptions may include physical objectives, activities, facial expressions, or test results.

Parsimony is not about taking the fastest route. Rather, it’s about finding the most efficient, comprehensive, and effective path possible. If there is a simpler yet equally thorough solution, this is the desired choice. This simplicity also makes communication easier, therefore increasing the chances that concepts are understood. 

In the spirit of parsimony, let’s break it down. Parsimony is all about:

  1. Using the fewest assumptions.
  2. Choosing the simplest explanation that fits the evidence.

What the Critics Say

Sounds simple enough, right? It may sound straightforward, but it requires discipline to apply effectively. Unfortunately, it’s easy for psychologists to overcomplicate things. Critics worry that there is a broad gray area in the process of parsimony psychology, and this can make it difficult to explain complicated behaviors and cognitive processes.[2]

Final Thoughts

physiological sciences such as biology and chemistry, it can also be used to help individuals overcome mental health symptoms.

If you are looking for the simplest and most accurate explanations for brain processes and human behaviors in your psychological treatment, then keeping things simple is probably the right approach for you.


  1. Borowski, S. (2012, June 12). The origin and popular use of Occam’s razor. American Association for the Advancement of Science. https://www.aaas.org/origin-and-popular-use-occams-razor
  2. Battig, W. F. (1962). Parsimony in Psychology. Psychological Reports, 11(2), 555–572. https://doi.org/10.2466/pr0.1962.11.2.555
Karen Doll, Author

Karen Doll has been a Licensed Psychologist in the Twin Cities for 20 years, working in organizational consulting. She leverages her education in Clinical Psychology with her leadership assessment expertise in her practice. She is an executive coach focusing on helping people maximize their potential.

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