Horoscopes – why we believe in them

When reading horoscopes, we often find sentences like: "Sometimes you are extroverted, sociable, and open-minded, sometimes rather introverted, skeptical, and reserved." If you feel that this statement applies to you, you're not alone. Horoscopes often seem to be very accurate; an observation that might be attributed to the Barnum effect.

Note: This article was already reviewed and is published in the German version of In-Mind.

Fig 1: Almost half of the German population reads horoscopes at least sometimes.

Glamour UK, The Sun, Daily Mail, People Magazine - at first glance, very different print media; yet they have one thing in common: They contain horoscopes. The first horoscope was published in 1930 in England. The "Sunday Express" published it at the time in honor of the newly born Princess Margaret; the birth of the princess thus also marked the birth of the horoscope.

Horoscopes remain very popular to this day. 39 percent of Germans state that they read horoscopes at least occasionally. And I admit, I am one of them. Even though I know that planetary constellations have no impact on my love life or could bring me an unexpected windfall, the wording in horoscopes always seem to fit my current situation. Why is that?

The Barnum-effect might give an answer to this question. You may have come across the name Barnum while watching Netflix: The movie "The Greatest Showman" tells the story of Phineas Taylor Barnum, an American businessman from the 19th century. Barnum opened a circus at the time, which featured not only animals and dancers but also magicians, giants, dwarfs, and a supposed mermaid, making him a pioneer of circus. The participants of the circus were exotically advertised: "See the snake woman - she walks, she talks, she breaths the air around us." A rather empty claim, as an American psychologist noted at the time ("of course she does"); thus referring to the finding that trivial statements apply to almost anyone as the Barnum effect [1].

Fig 2: The name of the Barnum effect is borrowed from a circus pioneer who offered "a little something for everyone" in his cabinet of curiosities.

The Barnum effect suggests that individuals interpret statements in a manner that makes them feel personally relevant [2], particularly when these statements are brief, ambiguous, two-sided, and positive in nature [3]. Typical examples include "You may like a little change in your life" (vague), "You are spontaneous, full of joy, and very emotional - but you are also quite agitated and quickly ready to turn the mood into anger and aggression" (two-sided), or "You are optimistic and powerful and liked by others" (positive). Statements that apply to these characteristics are referred to as Barnum statements.

The Barnum effect, also known as Forer effect, was initially demonstrated in 1949 by the psychologist Bertram Forer. To test the Barnum effect, he presented students with different Barnum statements, such as “You have a great need for other people to like and admire you”, “You have a tendency to be critical of yourself”, “Disciplined and self-controlled outside, you tend to be worrisome and insecure inside” or “While you have some personality weaknesses, you are generally able to compensate for them”.

It was assumed that these Barnum statements would serve as diagnostic indicators of personality, despite their general nature. To test this, Forer presented the students 13 Barnum statements, which they were asked to rate on a scale from 0 (low) to 5 (perfect). Two evaluation criteria were employed: the extent to which the statements were deemed suitable for unveiling personality traits overall, and the extent to which they were considered effective in revealing fundamental characteristics of one's own personality. Additionally, students were asked to indicate whether they perceived the statements as true or false in relation to their own personality.

Subsequently, when asking the students to raise their hands if they believed the presented statements to be suitable as a personality test, the entire class raised their hands. This result foreshadowed the findings of the following statistical analysis: The students considered the Barnum statements to be a reliable test for measuring their personality traits.

But why do we interpret statements as if they were specifically tailored to us, even though they clearly apply to most people? A closer examination of Barnum statements sheds light on this phenomenon: Barnum statements offer ample room for interpretation. For example, the term "other people" (to like and admire you) lacks specificity. Similarly, the degree of “tendency” (to be critical of yourself) can vary and the kind of “weaknesses” we compensate for is left to individual interpretation. Thus, such statements can generally be accepted, applying universally, much like the statement "You have two eyes".

However, merely having two eyes is not sufficient for distinguishing one person from another. Additional features such as eye color, shape, and length of eyelashes are necessary to do so. Similarly, in terms of personality, the presence of weaknesses and strengths alone does not differentiate one individual from another. It is the unique combination of individual weaknesses and strengths that sets us apart. While some may lack in listening skills, they thrive in entertaining others. Conversely, others may not be the best singers but demonstrate exceptional dancing skills. Thus, since Barnum statements allow for subjective interpretation of their ambiguous content, they tend to garner widespread agreement.

However, it is not surprising that we agree upon Barnum statements given their wording. What’s truly surprising is our inclination to perceive these statements as reflective of our own personality, as if they accurately depict what makes us uniquely special. For example, in one experiment, participants were presented with both an authentic psychological evaluation, personalized for each individual, and a description consisting solely of stereotypical and vague statements applicable to all participants (i.e., Barnum statements). Interestingly, participants found the test data based on Barnum statements to be more credible than the unique psychological assessment [4].

Despite our ability to distinguish between authentic, trivial, and false feedback, we perceive trivial feedback as the most reliable indicator of our personality [5]. This suggests that the awareness of Barnum statements’ general nature does not deter us from deeming them as accurate. Additionally, it seems irrelevant whether the personality feedback comes from psychologists, astrologers, or a computer [6][7].

Fig 3: General statements are more likely to be believed than actual psychological reports.

In 1979, Michel Gauquelin provided compelling evidence that horoscopes also exhibit Barnum-like characteristics. Gauquelin sent what was allegedly an individually customized horoscope to participants. He then asked the participants to evaluate how well the personality traits and challenges depicted in the horoscope matched their own experiences. Remarkably, 90% of the participants reported a strong resonance with the description. However, it was later revealed that the apparently personalized horoscope for each participant was actually identical, derived from the birth data of a serial killer.

Adding an insertion like "for you" to a horoscope further enhances its credibility. Feedback that seems customized to our individuality is perceived as even more accurate [6]. At the same time, interventions can help mitigate the Barnum effect. When participants are informed that the Barnum effect is a cognitive distortion and how it operates, they perceive Barnum statements as less accurate [8].

However, there is also criticism regarding the assessment of the Barnum effect. As you may already have noticed, the Barnum effect is often measured by asking participants to rate the accuracy of the presented Barnum statements. Based on these evaluations, individuals exhibiting the Barnum effect are occasionally labeled as gullible. Yet, it is not inherently wrong to perceive Barnum statements as fitting, as they usually are. As mentioned earlier, Barnum statements do apply, but not specifically to me as an individual; rather, they apply to almost all people. Thus, even though they apply, Barnum statements are unable to differentiate between individuals.

Andersen and Nordvik [9] therefore propose additional criteria to examine how we perceive Barnum statements. In addition to accuracy, the authors asked participants whether they consider the statements to be unique and informative. Here, it was found that Barnum statements have a disadvantage compared to genuine feedback. Thus, it seems that we recognize the inability of Barnum statements to effectively differentiate among individuals.

Despite research indicating that the Barnum effect independent of age [10], younger individuals, particularly, tend to believe in horoscopes [11]. One possible explanation for the appeal of horoscopes among younger generations might be their capability to reduce feelings of uncertainty [12]. For example, research indicates that especially young adults suffer from the uncertainty associated with COVID-19 [13] and the war against Ukraine [14].

Barnum statements aren't exclusive to horoscopes; marketing experts also leverage them. For instance, on Spotify's “Recommendations for You”, there's an abundance of podcasts listed, ensuring there's something to suit everyone’s taste.

Barnum statements can also be found in tarot, as well as in pseudo-personality tests on the internet. These tests, claiming to unveil your inner self, often feature vague statements that can apply to anyone. For example, they might say, “You exhibit moments of extroversion, sociability, and openness, as well as introversion, skepticism, and reserve”. Thus, it's essential to scrutinize such statements. Are they genuinely informative? Do they feel distinctively tailored? And do they genuinely reflect who I am? Or am I merely encountering a Barnum statement? Regardless of the answer, one thing is certain: This text leaves an impression on you.

Fig 4: Barnum statements can be found not only in horoscopes, but also in the tarot or in pseudo-personality tests.


[1] P. E. Meehl, "Wanted – A good cookbook," American Psychologist, vol. 11, no. 6, pp. 262-272, 1956.

[2] B. R. Forer, "The fallacy of personal validation: a classroom demonstration of gullibility," The Journal of Abnormal and Social Psychology, vol. 44, no. 1, pp. 118-123, 1949.

[3] N. D. Sundberg, "The acceptability of 'fake' versus 'bona fide' personality test interpretations," The Journal of Abnormal and Social Psychology, vol. 50, no. 1, pp. 145-147, 1955.

[4] M. R. Merrens and W. S. Richards, "Acceptance of generalized versus 'bona fide' personality interpretation," Psychological Reports, vol. 27, no. 3, pp. 691-694, 1970.

[5] M. E. Harris and R. L. Greene, "Students' perception of actual, trivial, and inaccurate personality feedback," Journal of Personality Assessment, vol. 48, no. 2, pp. 179-184, 1984.

[6] C. R. Snyder and G. R. Larson, "A further look at student acceptance of general personality interpretations," Journal of Consulting and Clinical Psychology, vol. 38, no. 3, pp. 384-388, 1972.

[7] R. E. Ulrich, T. J. Stachnik, and N. R. Stainton, "Student acceptance of generalized personality interpretations," Psychological Reports, vol. 13, no. 3, pp. 831-834, 1963.

[8] J. Rodríguez-Ferreiro, M. A. Vadillo, and I. Barberia, "Debiasing Causal Inferences: Over and Beyond Suboptimal Sampling," Teaching of Psychology, p. 00986283211048394, 2021.

[9] P. Andersen and H. Nordvik, "Possible Barnum effect in the Five Factor Model: Do respondents accept random Neo Personality Inventory–Revised scores as their actual trait profile?" Psychological Reports, vol. 90, no. 2, pp. 539-545, 2002.

[10] A. Furnham and S. Schofield, "Accepting personality test feedback: A review of the Barnum effect," Current Psychology, vol. 6, no. 2, pp. 162-178, 1987.

[11] F. Zandt, "Jüngere Deutsche glauben eher an Horoskope," [Online]. Available: https://de.statista.com/infografik/26016/glaube-an-vorhersagen-aus-horos.... [Accessed: Mar. 27, 2024].

[12] G. Weimann, "The prophecy that never fails: On the uses and gratifications of horoscope reading," Sociological Inquiry, vol. 52, no. 4, pp. 274-290, 1982.

[13] F. Glowacz and E. Schmits, "Psychological distress during the COVID-19 lockdown: The young adults most at risk," Psychiatry Research, vol. 293, p. 113486, 2020.

[14] A. Kurapov, V. Pavlenko, A. Drozdov, V. Bezliudna, A. Reznik, and R. Isralowitz, "Toward an understanding of the Russian-Ukrainian war impact on university students and personnel," Journal of Loss and Trauma, vol. 28, no. 2, pp. 167-174, 2023.


Picture 1: Darkmoon_Art via pixabay

Picture 2: Jonathan Borba via pexels

Picture 3: Sora Shimazaki via pexels

Picture 4: valentin_mtnezc via pixabay 

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