The science that studies the association of heavenly bodies and lives on earth is astrology. There is an acceptance among society and in history that the stars can guide and predict human life. In ancient history, people used the stars to anticipate the change of seasons, to judge the best time to plant crops, to measure the length of time for pregnancy, etc. From that practice came the belief that in turn, the stars could influence or prophesy lives here on earthy. Though having waned in influence, it still maintains it’s popularity in our present day and age. Why is there such an ongoing belief it its accuracy?
One reason why people believe in astrology and think it works is that they think it can be used to help understand personality and give accurate personality predictions. Most people only read their own horoscope so do not realise how vague they actually are and that the traits suggested by signs are in fact universal. Everybody behaves in each of these ways at various times, so no matter what your sign is it will agree with a trait you already possess. If astrologers can predict someone's personality from their birth chart (and thus the position of the stars and planets at the time of birth) as suggested, then astrologers using charts should consistently outperform astrologers not using charts, i.e. those just guessing.
The basis of personality prediction is also a bit dubious. Modern astrologers claim their 'science' is not based on magical associations, but its history shows this to be false. Astrology flourished in Ancient Greece where they deified the planets. People where meant to take on the characteristics of the god they were born under. The associations were never based on empirical research but still form the basis for modern astrological predictions.
People also believe that astrology can make accurate predictions in general. After any notable event articles appear in astrology journals showing correspondence between the event and its astrological chart. However, this means nothing unless the chart can predict the event in advance. Scientists analyzed a total of 240 earthquake predictions by 27 astrologers and found their accuracy to be worse than guessing. Culver and Ianna surveyed 3,011 specific predictions made from 1974-1979 in U.S. astrology magazines. Only 338 (11%) were correct, and many of these could be attributed to shrewd guesses, vagueness or inside information.
Astrology is also used to aid career choices. In the early 1980s Alan Smithers examined the jobs and birth dates of 2.3 million people listed in Britain's 1971 national census. The results were reported over four days in The Guardian in March 1984. Before beginning analyses 16 expert astrologers made predictions of the correlations that would be found. The results were marginally better than chance. However this could be partly explained by seasonal trends. A 10% sample from the same census showed that the professional and managerial classes in Britain are significantly more likely to have there babies in spring and summer, whereas the opposite applies to manual workers and the unskilled. The results may also be due to self-attribution, people choosing a particular line of work because it matches their star sign. It would only require 1 person in 60 to think this way to account for The Guardian results. As Dean showed, 1 person in 3 believes in astrology enough to shift their self-image in the direction their star sign suggests. It would only need 1 in 20 of those to choose a job accordingly.
Another claim made by astrology is that people should choose partners born under compatible star signs. However studies have shown that sun signs have no influence on marriage or divorce. For instance Bernard Silverman found no link among the records of 2978 couples who married and478 couples who divorced in Michigan during 1967. Astrologers also widely disagree as to which sun signs are compatible.
Another use for astrology is for counseling purposes. Skaft tested the effect of introducing popular astrology into personal and vocational counseling. She found that this provides a focal point for discussion and often stimulates clients to talk openly about them, and the mutual interest quickly creates closeness and rapport that would otherwise take many sessions to establish. The focus on individual qualities also meets the clients need to feel special. Therefore astrology can be valuable and work without necessarily being true. An astrologer can provide good, practical advice with a sympathetic ear, which could cost far more if provided by a psychiatrist.
Self-fulfilling prophecies help to maintain people's beliefs in astrology. People act in ways to ensure that their beliefs are correct. Hindsight bias, or the I-knew-it-all-along effect, is when once we know the answer we find plenty of evidence to support it, so we feel we knew it all along when in fact we did not. Therefore, once a match has been found between a chart and a person it will be hard to see how it could be any other way. Self-attribution is another self-fulfilling prophecy which involves people role playing their birth chart, for example, choosing a particular line of work because it matches their star sign as mentioned earlier.
Although one of the main reasons people belief in astrology is that they think it works, and can be used to make valid predictions, personality assessment, career choices and for compatibility, evidence does not seem to support this. There are also a number of psychological and social reasons that can explain why people belief in astrology and why this belief is maintained. Some of the most potent of these human judgment biases are the Barnum effect, or how people accept vague statements as being specific for them, how people try to avoid cognitive dissonance and the illusory correlation effect, seeing correlations where none exist.
