Over 2300 years ago, the Babylonians came up with the idea that the gods lived among the stars and other celestial objects, and were able to impose their will on humanity by controlling the destinies of individuals and nations alike.
The Babylonians divided the sky into 12 “slices”: which we now know as the signs of the zodiac… Taurus, Pisces, etc. There are many variations of astrology, but they are all founded upon the idea that celestial objects can influence a person’s personality and destiny.
Today, according to a Gallup poll, 25% of American believes in Astrology. In this article, we’ll investigate why horoscopes and astrology sometimes appear to be correct by reviewing the concept of subjective validation, the Forer Effect, and Gauquelin’s famous horoscope experiment; we’ll take a look at what an astronomer has to say about astrology; we’ll review some of the logical issues with astrology; and finally, we’ll take a look at how easy it is to debunk horoscopes yourself.
Subjective Validation and the Forer Effect
“Subjective validation” occurs when two unrelated or random events are perceived to be related because a belief, expectancy, or hypothesis demands a relationship. Thus, people find a connection between the perception of their personality and the contents of their horoscope.
The concept of subjective validation was put to the test in 1948 by psychologist Bertram R. Forer. Forer gave a personality test to each of his students. Afterward, he told his students they were each receiving a unique personality analysis that was based on the test’s results, and to rate their analysis on a scale of 0 (very poor) to 5 (excellent) on how well it applied to themselves.
The analysis presented to the students was as follows:
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, 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.
The trick? In reality, each student received the exact same analysis: On average, the rating was 4.26/5 (that is, the students found their “personal” analysis to be 85% accurate). It was only after the ratings were turned in was it revealed that each student had received identical copies assembled by Forer from various horoscopes.
As can be seen from the profile analysis, there are a number of statements that are vague and could apply equally to anyone. These statements later became known as Barnum statements, after P.T. Barnum, who used them in his performances, allegedly stating “there’s a sucker born every minute.”
Later studies have found that subjects give higher accuracy ratings if the following are true:
- the subject believes that the analysis applies only to him or her (for example, a horoscope)
- the subject believes in the authority of the evaluator (for example, a psychic)
- the analysis lists mainly positive traits (for example, most daily horoscopes)
Guaquelin’s Horoscope Experiment
In another experiment, the famous French Astrologer, Michael Gauquelin, offered free horoscopes to any reader of Ici Paris, if they would give feedback on the accuracy of his supposedly “individual” analysis. He wanted to scientifically test the profession of astrology. As with Forer’s experiment, there was a trick: he sent out thousands of copies of the same horoscope to people of various astrological signs – and 94% of the readers replied that his reading was very accurate and insightful.
What they didn’t know was that the horoscope was that of a local mass murderer, Dr. Petiot, who had admitted during his trial that he had killed 63 people. This is clearly another case of subjective validation where subjects focus on the hits of some general analysis that’s supposed to be unique to them.
An Astronomer’s Opinion
So what does science have to say about astrology? Phil Plait (a veritable astronomer, not astrologer) summarizes his scientific opinions as follows:
- There is no force, known or unknown, that could possibly affect us here on Earth the way astrologers claim. Known forces weaken too fast, letting one source utterly dominate (the Moon for gravity, the Sun for electromagnetism). An unknown force would allow asteroids and extrasolar planets to totally overwhelm the nearby planets.
- Like psychics, astrologers tend to rely on human’s ability to remember “hits” and forget ”misses” – a form of selective bias. Even an accurate predictions may be due to simple chance.
- Study after study has shown that claims and predictions made by astrologers have no merit. They are indistinguishable from chance, which means astrologers cannot claim to have some ability to predict anyone’s life’s path or destiny.
- There is harm in astrology. It weakens people’s ability to rationally look at the world, an ability we need now more than ever.
Without going into further detail, I highly recommend reading the full article on his website.
Logical problems with horoscopes and astrology:
1) Since the Earth spin drifts slightly, the constellations shift by at 1 degree every 72 years. Over time, roughly 2000 years, the signs of the zodiac actually get shifted over by one. So what’s your sign? It should actually be shifted one over from what you think it is… that is, you should be reading the horoscope from the star sign before yours!
2) 2) Horoscopes are cast from the time of birth, not from the time of conception. What is considered the time of birth? When the water breaks? When the head appears? When the feet are out? What about a c-section? You would think that the planets would begin their influence on the unborn fetus for the duration of its development.
3) 3) When you read your horoscope, you’re sharing it with roughly 1/12th of the world’s population. Doesn’t it seem strange that so many people from across the entire planet should share the same fate on any given day?
4) 4) Why are people born on the same day each year so different? Surely, if the gods or planets or whatever had some sort of true influence, then anyone born on the same day each year should be very, very similar.
5) 5) The traditional planets of our solar system (i.e. none of the recently discovered planetary candidates), were named after Roman gods. This assignment was completely arbitrary. There might have been some logic behind it (Mars is red, war has blood, etc.), but overall there is no real reason to think that just because Venus was named after the goddess of love, that it should hold any sway over one’s relationships. If the “effects” of the planets on people, had any real relationship to the planets themselves, then Venus should be the ruler of bad gas, not love.
6) 6) Many astrological terms are holdovers from a time when the Earth was believed to be the center of the universe. We are clearly not at the centre of the universe.
7) 7) What about Uranus, Neptune and Pluto, which were only discovered within the past 250 years? In ancient times, these outer planets were unobservable with the naked eye. Astrologer’s based their system and equations upon the seven planets they believed revolved around the Earth. If the position of the planets has an influence upon human behavior and events, then how could any of the beliefs have been correct, if these celestial objects were missing from the “equation”?
8) 8 ) Here’s a logical fallacy: the appeal to tradition. Just because lots of people practice a tradition, like astrology, says nothing of its viability. Simply because many people may believe something says nothing about the fact of that something. For example, many people during the Black plague believed that demons caused disease. The number of believers said nothing at all about the actual cause of disease.
Most importantly, none of the detailed statistical studies that have looked at astrology have found any merit in it. For example, a psychologist from Michigan State University, Bernard Silverman, looked at 2,978 married couples and 478 couples who divorced. He found absolutely no correlation between which couples divorced, and which couples were born under alleged “incompatible” signs.
A Comprehensive Study Measuring the Performance of Astrology and Astrologers
Geoffrey Dean and Ivan W. Kelly’s report “Is Astrology Relevant to Consciousness and Psi?” looked at the efficacy of astrology noted and concluded the following:
- A large-scale test of persons born less than five minutes apart found no hint of the similarities predicted by astrology.
- Meta-analysis of more than forty controlled studies suggests that astrologers are unable to perform significantly better than chance even on the more basic tasks such as predicting extraversion.
- More specifically, astrologers who claim to use psychic ability perform no better than those who do not.
“Our concern in this article has been to measure the performance of astrology and astrologers. A large-scale test of time twins involving more than one hundred cognitive, behavioural, physical and other variables found no hint of support for the claims of astrology. Consequently, if astrologers could perform better than chance, this might support their claim that reading specifics from birth charts depends on psychic ability and a transcendent reality related to consciousness. But tests incomparably more powerful than those available to the ancients have failed to find effect sizes beyond those due to non-astrological factors such as statistical artifacts and inferential biases.”
Debunking Horoscopes and Astrology Yourself
It should be easy enough for anyone to debunk horoscopes or astrology. All you need to do is take a sample horoscope for the same sign on the same day across various networks. If horoscopes are legit, then all five horoscopes should be in line with each other – giving the same type of advice to their followers. Below, you’ll find a small sample for my sign, Taurus, for December 20th, 2010:
Keep in mind, this horoscope applies to roughly 583 million people across the planet (taking a quick estimation of the number of people that are Taurus on Earth)
Horoscope #1: From www.horoscope.com
“You need bigger and longer hugs than usual today, Taurus. A powerful force is moving through your life and trying to shake things up. Don’t stoop to the level of petty argument and verbal sparring. The more you resist the opposition, the more stubborn and unwieldy the situation becomes. Make sure you have a good hold on your emotions before you leave the house.”
Horoscope #2: From www.theglobeandmail.com
“Be careful what you agree to over the next two or three days because the approaching lunar eclipse will blur the line between fact and fantasy. This is not a good time to be reckless with your money, or your reputation.“
Horoscope #3: From http://www.spiritnow.com/horoscopes (Sylvia Browne’s site)
“Although the fun element will be lacking almost from start to finish, this is certainly a useful day. Don’t be surprised if you notice some very tiny changes over an ongoing matter. These nudging or very slight improvements might not be much to celebrate, but they will indicate further improvements to come!”
Horoscope #4: From www.nationalpost.com
“Stay on top of your bank account and your bills today because something unexpected might be taking place. This could affect inheritances, shared property, insurance matters, or anything you hold jointly with others. Make sure you aren’t overdrawn. (Nobody likes surprises like that.)”
Horoscope #5: From www.astrology-online.com
“Focus on your domestic scene. Get together with friends or relatives. Calm down and take a step back. You can’t win and they won’t listen.”
In this very small sample set, it’s clear that they have nothing in common – except that the two Canadian newspapers (the Globe and Mail and the National Post) both reference “money”… but given that the holidays were right around the corner, “money” was on everyone’s mind already, so I will discount that statement as an appeal to the masses.
I deliberately paid close attention to each of my 5 horoscopes for December 20th, and nothing came true. I focused on my domestic scene – no issues. I stayed on top of my bank accounts – no issues. There were no “slight improvements” to note. I didn’t need bigger or longer hugs.
Conclusion: There is no legitimate scientific evidence to support astrology and horoscopes.
Why do 25% of Americans, despite the lack of evidence, continue to believe in Astrology and horoscopes? “Many people quite simply just want to believe,” says Brian Cronk, a professor of psychology at Missouri Western State University. “The human brain is always trying to determine why things happen, and when the reason is not clear, we tend to make up some pretty bizarre explanations.”
Horoscopes and astrology are for fun, period. If you enjoy reading them and you’re a fan of subjective validation, and you want to spend your hard-earned disposable income on books, 1-900 numbers, and readings, then by all means, go ahead. But don’t claim astrology real, and don’t claim it’s science. And by all means, don’t let your horoscope affect important life decisions – there’s a reason why websites and 1-900 numbers have a disclaimer stating that their “advice” is “for entertainment purposes only”.
^ Marks, David F (2000). The Psychology of the Psychic (2 ed.). Amherst, New York: Prometheus Books. pp. 41. ISBN 1573927988. http://search.barnesandnoble.com/The-Psychology-of-the-Psychic/David-F-Marks/e/9781573927987/?itm=1.
^ Forer, B.R. (1949). “The fallacy of personal validation: A classroom demonstration of gullibility”. Journal of Abnormal and Social Psychology (American Psychological Association) 44 (1): 118–123. doi:10.1037/h0059240.
^ Dickson, D.H.; Kelly, I.W. (1985). “The ‘Barnum Effect’ in Personality Assessment: A Review of the Literature”. Psychological Reports (Missoula) 57 (1): 367–382. ISSN 0033-2941. OCLC 1318827.