Astrology and the Forer Effect

by | Dec 10, 2018


Do you check your horoscope regularly? If so, you aren’t alone. According to sociologist Nick Allum of the University of Essex about half of Americans read their horoscope at least occasionally and about 25% of Americans believe astrology has predictive power and is scientific.

Astrology is a belief that the relative positions of the sun and the planets can influence humans. A horoscope is a prediction of how those arrangements of celestial bodies will affect people born within one of 12 zodiac signs. Supposedly, people born within the same sign share personality characteristics and the planets will effect them similarly. There is no scientific evidence for astrology and belief in astrology is inversely related to level of education.

Why do so many people believe in astrology? A leading theory is that horoscopes sound correct due to the “Forer Effect” (also called the “Barnam Effect”).  Bertram Forer was a psychologist and is famous for a personality test he gave a group of students 1948. He provided them with a personality assessment for them to complete and then told them that he would provide them a description of their personalities based on the assessment. When the students received their personality evaluations he asked them to rank their perceived accuracy of the description on a scale of 1 to 5 (with 5 being a spot on description).  However, unbeknownst to the students, they all received the exact same personality description – just a jumble of statements Dr. Forer had taken from horoscopes. Here’s what they each received:

You have a great need for other people to like and admire you. You have a tendency to be critical of yourself. You have a great deal of unused capacity which you have not turned to your advantage. While you have some personality weaknesses, you are generally able to compensate for them. Disciplined and self-controlled outside, you tend to be worrisome and insecure inside. At times you have serious doubts as to whether you have made the right decision or done the right thing. You prefer a certain amount of change and variety and become dissatisfied when hemmed in by restrictions and limitations. You pride yourself as an independent thinker and do not accept others’ statements without satisfactory proof. You have found it unwise to be too frank in revealing yourself to others. At times you are extroverted, affable, and sociable, while at other times you are introverted, wary, reserved. Some of your aspirations tend to be pretty unrealistic. Security is one of your major goals in life.

How well did the students think the above described them? Many gave the description a 5 out of 5. The overall average was 4.26. The experiment is still commonly conducted today and modern students nearly always average greater than a 4 out of 5 for accuracy.

Thus, the Forer Effect describes the phenomenon of seeing our own traits in any positive personality description.

The Forer Effect is also why horoscopes can seem correct. I’m an Aries and in researching this IFOD I read the characteristics of an Aries male. It was 90% spot on! “Rapid fire wit!” Check. “A warrior for what they believe to be right and true!” Yes! “Driven and assertive.” Totally! I was like “wow, that’s amazing.”

To check, I then read the description of a Gemini male. “Jovial, good natured.” Me again! “Gift for gab and like to tell stories.” That’s me. “A Gemini loves to learn and share his knowledge.” OMG – spot on. Also a really good description of me!  How about Virgo? “Extremely intelligent and always parsing information.” Yes. “A tendency to be OCD.” Totally me. And so on . . .

Note that the Forer Effect can be found beyond horoscopes. For example, a criticism of the Myers-Briggs is that it is not an accurate or robust assessment but we accept its results due to the Forer Effect. Dr. Susan Whitbourne writing in Psychology Today  criticized the Myers-Briggs for many failings, including lack of scientific foundation and explained why people fall for the Myers-Briggs: “Oddly enough, people are so willing to believe anything about their personalities that they’ll fall for even the lamest explanations.”


  1. Myers-Biggs in a nut shell – Late last fall, the Indians on the Aamjiwnaang Nation reservation in Grand Bend, Canada, asked their new chief if the coming winter was going to be cold or mild. Since he was a chief in modern society, he had never been taught the old secrets. When he looked at the sky, he couldn’t tell what the winter was going to be like. Nevertheless, to be on the safe side, he told his tribe that the winter was indeed going to be cold, and that the members of the village should collect firewood to be prepared. Being a practical leader, after several days, he got an idea. He called the Canada Weather Service and asked, ‘Is the coming winter going to be cold?’ ‘It looks like this winter is going to be quite cold,’ the meteorologist at the weather service responded. So the chief went back to his people and told them to collect even more firewood in order to be prepared. A week later, he called the Canada Weather Service again. ‘Does it still look like it is going to be a very cold winter?’ ‘Yes,’ the man at Weather Service again replied, ‘it’s going to be a very cold winter.’ The chief again went back to his people and ordered them to collect every scrap of firewood they could find. Two weeks later, the chief called the Canada Weather Service once more. ‘Are you absolutely sure that the winter is going to be very cold?’ ‘Absolutely,’ the man replied. ‘It’s looking more and more like it is going to be one of the coldest winters we’ve ever seen.’ ‘How can you be so sure?’ the chief asked. The weatherman replied, ‘The Indians are collecting one Hell-of-a-lot of firewood.”

  2. Maybe Gemini is your rising sign.

    • So true!


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