Short answer: the correlation is real, but where does it sit?
In some personality surveys, people born under signs described as "fire" or "air" sometimes rate themselves as more extroverted than people under other signs. But on closer look, that difference appears only among those who already knew what astrology says about their sign. When the question gives no hint of astrology, or when respondents are unfamiliar with those descriptions, the difference usually vanishes. This is a real correlation in the data, but the cause does not lie in the celestial bodies.
What is the self-attribution effect?
Self-attribution is the act of using descriptions already available in culture to understand and narrate oneself. People do not invent a personality out of nothing: as they grow up, they hear friends, family, books, and social media talk about "Aries people" or "Cancer people." Those descriptions become part of the vocabulary they use to observe themselves: "I am hot-tempered, probably because I am Aries." Each time they describe themselves this way, they both register a trait and reinforce that view of themselves.
To be clear: this is not about someone deliberately lying on a questionnaire. Respondents are honest; they are simply answering from a ready-made frame of reference. This mechanism applies to believers and non-believers alike, as long as they have encountered the popular descriptions.
Why did the 1978 survey draw attention?
Kind of knowledge: UnprovenNot enough evidence. Someone has claimed it, but no source or study is strong enough to confirm it. The five labelsIn 1978, J. Mayo and colleagues published a survey in The Journal of Social Psychology, reporting a correlation between astrological factors and some personality traits, including extroversion. The result drew attention because it ran against the usual expectation of personality researchers: if astrology has no plausible mechanism of influence, there should be no notable correlation at all.
This result needs to be placed at the right level: it is a survey, not a controlled experiment isolating the belief factor. And by this article's convention, a correlation in one sample does not by itself reveal a mechanism. Mayo and colleagues recorded a phenomenon; the "why" question remained open.
That same year, A. G. Smithers and H. J. Cooper published in the same journal a study on personality and season of birth, recording a seasonal distribution pattern similar to Mayo's result. These two authors only noted the phenomenon; they did not claim it as evidence for astrology.
What did the replications say?
Kind of knowledge: UnprovenNot enough evidence. Someone has claimed it, but no source or study is strong enough to confirm it. The five labelsK. Pawlik and L. Buse replicated the work in 1979 in Zeitschrift für Sozialpsychologie and found the key point: the correlation appeared only among people who already knew the traits astrology assigns to their sign. The group unfamiliar with those descriptions produced no similar correlation. This is precisely the signature of self-attribution.
Marlis Jackson and Martin S. Fiebert published in 1980 in The Journal of Psychology, finding no correlation between extroversion and Sun sign across 174 students.
Jan J. F. van Rooij published in 1994 in Personality and Individual Differences, showing that the effect appeared only among people knowledgeable about astrology, and grew stronger when respondents were hinted that the study related to astrology. The detail "stronger when hinted" matters: it shows the difference is not a biological constant but a context-dependent phenomenon.
Catherine S. Fichten and Betty Sunerton published in 1983 in The Journal of Psychology, noting that knowing one's sign in advance made readers judge personality descriptions as more accurate. This is another piece of the same mechanism: once a frame is in place, people readily see a description as "fitting them."
| Study | Data scope | Main result |
|---|---|---|
| Mayo et al., 1978 | Survey, The Journal of Social Psychology | Reported correlation between astrological factors and personality, including extroversion |
| Smithers and Cooper, 1978 | Same journal | Seasonal distribution pattern similar to Mayo |
| Pawlik and Buse, 1979 | Replication | Correlation only among those who knew the traits assigned to their sign |
| Jackson and Fiebert, 1980 | 174 students | No correlation between extroversion and Sun sign |
| Fichten and Sunerton, 1983 | Readers of personality descriptions | Knowing one's sign in advance made descriptions seem more accurate |
| van Rooij, 1994 | Replication | Effect only among those knowledgeable about astrology, stronger when hinted |
Why do some surveys still find "fire" signs more extroverted?
Because the survey sample cannot separate the group that "already knew the descriptions of their sign" from the rest. If most participants have read horoscopes in newspapers, or heard friends say "Aries people are hot-tempered," their answers are already tinged with that knowledge. The correlation appears not because the Sun was in a certain position at birth, but because culture assigned the label first and people then assigned that label to themselves.
Kind of knowledge: School: Western astrologySchool's interpretation. How one school or one book reads it; other schools may read it differently. The five labelsSome astrological schools hold that these descriptions reflect a real cosmic order, and that people finding them accurate simply confirms that order. This article's rule is: a system's own texts prove what the system says, not that what it says is true. The survey results above cannot adjudicate that cosmological question; they only show that most observable differences can be explained by psychological mechanisms.
One methodological point deserves note: according to Gerhard Mayer's overview in the Journal of Scientific Exploration, prior astrological knowledge can bias answers, including simple knowledge skimmed from newspapers or packaging. Mayer also notes that the Barnum effect, the tendency to see vague descriptions as "fitting oneself," is one of the well-known psychological mechanisms in this field.
How does this apply to "Tiger people are hot-tempered"?
Kind of knowledge: Folk beliefFolk belief. What people believe, avoid or pass on by word of mouth, recorded as a belief, not as a checked fact. The five labelsIn folk belief, people born in the Year of the Tiger are described as strong, hot-tempered, and fond of leading. The mechanism here is identical to the zodiac sign case: people hear that description from childhood, and when they observe themselves, moments of anger are remembered more vividly while calm moments are easily overlooked. Gradually, they narrate themselves using exactly the vocabulary culture has provided.
Kind of knowledge: UnprovenNot enough evidence. Someone has claimed it, but no source or study is strong enough to confirm it. The five labelsThere is no self-attribution research on Vietnamese zodiac animals or Five Elements destiny. Saying "the mechanism is the same" here is a reasonable hypothesis based on Western zodiac studies, not a result measured on Vietnamese people. To know for sure, a survey would need to separate the group that already knows the descriptions of its zodiac animal from the group that has never heard them, and compare against an independent personality scale.
It should also be stated clearly: the studies cited above were all conducted abroad, mainly on students and adults in the West, during the 1970s to 1990s. Those results do not automatically transfer to Vietnamese people, nor to systems like tu vi or tu tru, which use entirely different star placement and interpretation methods from Western astrology.
A true correlation can still have another cause
This is a general lesson, not specific to astrology. A correlation figure in data only says that two things change together; it does not say which causes which, nor that no third thing stands behind them. Here, the third thing is very likely cultural knowledge about zodiac signs. When that knowledge is removed from the equation, most of the difference disappears.
The usual way to distinguish in psychology is to split groups by level of astrological knowledge before asking. If the difference remains only in the knowledgeable group, we are looking at an effect of belief. If the difference persists in the group that knows nothing about astrology, then another explanation is needed. So far, published data lean toward the first possibility.
So should we call astrology "wrong"?
Kind of knowledge: UnprovenNot enough evidence. Someone has claimed it, but no source or study is strong enough to confirm it. The five labelsNo. The question "can astrology measure personality" is a narrow one, and the answer based on available data is: there is no evidence that Sun sign predicts personality once the respondent's knowledge is controlled for. But that does not deny that many people find these descriptions useful, that reading about one's sign can be an enjoyable way to reflect, or that astrologers can offer helpful conversations. The self-attribution effect and the Barnum effect are real; they explain why the experience is persuasive without needing the hypothesis that celestial bodies influence personality.
In other words, the distinction to keep is this: the subjective experience is real, the mechanism producing it is psychological and cultural, and the metaphysical question about the cosmos lies beyond what current data can answer.
