Psychologist’s Fallacy

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Psychologist’s Fallacy. Psychology Fanatic
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The psychologist’s fallacy is a thinking error introduced by American psychologist William James, describing the subjective observation of an external observer who wrongly assumes that their subjective interpretation represents an objective conclusion. Basically it is the fallacy of confusing an opinion (educated or not) with a supportable fact.

While William James was specifically referring to psychologists when he coined the term, we all routinely use this cognitive shortcut. We observe a few points of data from the external environment, plug the fragments of information into our memory banks of experience, and draw a subjective conclusion that we act on as if it is a fact.

We love the cognitive ease of this thinking fallacy, confidently drawing conclusion from partial information. Even though, we find security of leaning on a coherent story, we must check our conclusions, remembering that experiences and biases strongly influence perceptions. Accordingly, our subjective conclusions color our perception of reality and do not represent reality itself.

Key Definition:

Psychologist’s fallacy is when an external observer assumes that their subjective interpretation of someone else’s experience is an objective conclusion.

William James and the Psychologist’s Fallacy

James coined the word ‘psychologist’s fallacy’ in his book ‘Principles of Psychology.’ He wrote, “the great snare of the psychologist is the confusion of his own standpoint with that of the mental fact about which he is making his report. I shall hereafter call this the ‘psychologist’s fallacy’ par excellence” (2017). During this time, psychology was undergoing changes. Some referred to it as ‘a new psychology.’

P.D. Ashworth wrote that Williams “wrestled with the fundamental disjunction between the construction of external, third person causal models of psychological processes…and the understanding of the meaning in first-person experience” (2009). James warns “we must be very careful therefore, in discussing a state of mind from a psychologist’s point of view, to avoid foisting into it own ken matters that are only there for ours” (2017).

Any observed behavior is subject to interference by the observer. Whether in formal research, therapy, or casual observations, the person watching intrudes on the pure unobserved experience. Once we push deeper into the observed behavior by interpreting the meaning behind it, we bring with our interpretation all our personal knowledge, experience, and biases. Once we theorize what something means, we must proceed carefully, not ‘foisting’ all our person material used in these subjective findings onto the other person.

The Phenomenon of a Psychologist’s Fallacy Outside of Psychology

This thinking error is not exclusive to psychology. Certainly, I see it in psychology because of my brain full of psychology theory and research. However, strangely enough, my subjective judgements of others behaviors is not a nice balanced evaluation, drawing from a couple decades of research, my evaluations are heavily influenced by my last couple research projects. Our brains are primed by surrounding context.

Daniel Kahneman explains that each observation is like a ripple on a pond. Each small observed event intertwines with past and present in a complex network that forms ideas and feelings (2013).

Perhaps, our skill of assigning states of mind to behaviors is the underlying mechanism behind the psychologist’s fallacy. In psychology, we refer to this as ‘theory of mind.’ However, our theories rely on personal knowledge. Therefore, they may be wrong.

We often project our interpretations onto the person we are subjectively evaluating. I often hear police detectives proclaim on real crime drama that, “I knew they were guilty because I would not act like that if my wife was killed.” This subjective interpretation fuses the detectives feelings for his spouse, their unique relationship (children, shared life, etc…), the officers own psychological state (including childhood, exposures, etc…) and projects it onto a person they know little or nothing about. Sometimes, they may be right. The odd behavior may be because of their guilt. However, other times their odd or unexplainable behavior may be because of the countless things the detective does not know about the person they just met.

Examples of Psychologist’s Fallacy

A prime example of an everyday occurrence of the psychologist’s fallacy is when we casual observe someone sitting on a bench, looking off into space, with a blank expression, and droopy eyes. I immediately interpret that the person must be ‘sad.’ I infer on him a mental state based on my personal experience and understanding of facial expressions and emotions. My assessment may be correct, but, then again, it may be completely wrong.

Other examples of the psychologist’s fallacy are the following:

  • A parent who assumes that their interpretation of their child’s emotional state is always correct.
  • Someone who believes they know how their romantic partner feels.
  • When we attempt to soothe somebody experiencing trauma by relating a personal story, punctuated with “i know how you feel.”
  • Any belief that we know what some one is thinking, feeling, or experiencing based on an interpretation of their outward behavior.

Subjective vs. Objective Interpretations

T. Franklin Murphy wrote, “​making sense of experience is a bidirectional process—bottom-up and top-down. Energy flows up to the cortex, integrates with memories and then flows back to the body and out to surrounding others. Somewhere in this complex movement of energy and information, we create a theory—a deeper meaning—imposing beliefs on the unknown. We predict from a smile or a scowl whether a person is safe or dangerous, honest or deceiving, loving or manipulating. These predictions give direction to the responding action” (2019).

We create internal working models of the world. These models are “the internal mental representations we create of elements in our environment through repeated exposure. These representations become the models we use when interpreting new experiences” (Murphy, 2022). These internal working models interfere with objective interpretations.

Complexity and the Psychologist’s Fallacy

Complex adaptive systems, such as humans, rarely have a single identifiable cause. Our attributing of human behavior to a single identifiable cause ignores the mass of contributing causal factors (Axelrod and Cohen, 2001). All our theories are simplified, falling short of the massive complexities of true combined causes of a behavior. We do our best to understand, drawing wisdom from our observation but simultaneously understand that these perceptions are weighted by our knowledge, recent priming of context, and a host of other interferences. We can’t assume the person we are subjectively evaluating is operating under all the same knowledge and experiences, and therefore, there experience is different than our perception of their experience.

Verifying a Subjective Interpretation

Carl Jung explained we must verify subjective judgements. He wrote about one of his own subjective thoughts that he must “try to plant the results of my experience in the soil of reality; otherwise they would have remained subjective assumptions without validity” (1989).

The psychologist’s fallacy reminds us of the importance of empathy and open communication. While we can make educated guesses based on external cues, it is essential for us to recognize the limitations of these guesses and not mistake them for an objective truth. Engaging in active listening and seeking clarification from others may help us avoid this logical fallacy and foster genuine understanding. A little verification work, planting a subjective interpretation into the ‘soil of reality’ may help us weed out many of our incorrect theories relating to the ‘real’ experience occurring in the body and mind of another person.

Remember, our understanding of others is always filtered through our own subjective lens. By acknowledging this, we can approach interpersonal interactions with humility and respect, recognizing the uniqueness of each individual’s experience.

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Ashworth, P. D. (2009). William James’s “psychologist’s fallacy” and contemporary human science research. International Journal of Qualitative Studies on Health and Well-being, 4(4), 195-206.

Axelrod, Robert; Cohen, Michael D. (2001). Harnessing Complexity. Basic Books; Reprint edition.

James, William (1890/2017). The Principles of Psychology, Vols. 1-2. ‎ CreateSpace Independent Publishing Platform; Combined edition.

Jung, Carl G. (1961/1989). Memories, Dreams, Reflections. Vintage; Reissue edition.

Kahneman, Daniel ( 2013). Thinking Fast; Thinking Slow. Farrar, Straus and Giroux; 1st edition.

Murphy, T. Franklin (2019). Theory of Mind. Psychology Fanatic. Published 10-19-2019. Accessed 7-24-2023.

Murphy, T. Franklin (2022). Internal Working Models. Psychology Fanatic. Published 8-16-2022. Accessed 9-19-2022.

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