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The Universe At Your Fingertips Activity: Activities With Astrology

 

Introduction

Activity Description

Goals and Tips

Preparation

Astrology Defense Kit

Introduction

These activities help students to understand the difference between science and pseudoscience by investigating some of astrology's claims. Letting students have a good discussion can be very effective. We encourage you to read "Your Astrology Defense Kit" before doing these activities.

Students test the validity of astrology with three activities:

1. Charting birthdates of U.S. presidents

2. Comparing horoscopes in different newspapers

3. Attempting to identify their own horoscope from an unidentified list of daily predictions

This activity was written by Andrew Fraknoi (Foothill College and Astronomical Society of the Pacific) and incorporates suggestions by Diane Almgren, Daniel Helm and Dennis Schatz.
Copyright © 1995, Astronomical Society of the Pacific, 390 Ashton Ave., San Francisco, CA 94112. This activity may be reproduced for nonprofit purposes.

Activity Description

Activity 1: Testing Astrology with the Birthdays of the Presidents

Astrologers will tell you that the Sun sign (which is the sign of the zodiac the Sun was in when a individual was born) is a crucial factor for the occupation a person chooses and a strong determinant of overall personality as it relates to one's job. As an example of how we can test such a hypothesis, students can examine the birthdates of the 41 men who have successfully run for the job of President of the United States.

After all, it takes a certain kind of personality to be President (outgoing, well-spoken, ambitious). If personality and occupation are strongly affected by Sun sign, we should find that the birthdays of the Presidents are clustered in one (or a few) signs. If Sun signs do not affect personality and occupation, the Presidents' birthdays should be randomly distributed among the zodiac signs.

Students will fill out a worksheet to determine the astrological signs of the 41 Presidents and discuss their results. You will need to review the concept of random distribution before doing this activity.

How many Presidents do students expect to find under each sign if the birthdays of the 41 Presidents are randomly distributed among the 12 signs of the zodiac?

Since there are 41 people, chance would classify 3.4 people (41 people divided among 12 signs = 3.4 people per sign) into each of 12 random "bins." With only 41 data points, you might expect one or two fewer or one or two more Presidents in a given sign.

Extending the Activity:

Encourage students to discuss other ways to test this hypothesis. What occupations are also personality-driven but have more than 41 people in them? (As discussed in Your Astrology Defense Kit, one group of statisticians tested all the men who re-enlisted in the Marine Corps - definitely a personality related career choice!)

Activity 2: Horoscopes from Different Astrologers

In this activity, students compare horoscopes in different newspapers from the same day. Ask students to bring in newspapers or buy them yourself. You can also copy newspapers from a local library, although using photocopies reduces the psychological impact of the activity somewhat. The more newspapers you have, the better the activity.

Cut the horoscope sections out of the papers and distribute them to students. If possible, cut out the horoscopes in full view of the students for greater impact. Ask several students to read aloud the different horoscopes of one or more selected students from the various newspapers. Discuss the following questions:

1. How well do the predictions of different astrologer agree for that student's sign?

2. How specific are the newspaper statements?

3. In what ways could the statements apply to different people?

Have the students discuss some reasons why the predictions in astrology columns might be so general and vague. If there is time, continue the discussion by bringing up some of the "embarrassing questions about astrology" in Your Astrology Defense Kit.

Activity 3: Mixed-up Horoscopes

In this activity, students try to find their own sign from a variety of unidentified signs in a horoscope column. Use an astrology column from a recent newspaper (today, yesterday, or last weekend). It is best to use an out-of-town newspaper so students are not likely to have seen it. Cut out the horoscopes and remove the dates, signs and any telltale references to the sign, like "you're a real lion at times." Be sure to make a copy of the full column for yourself and put it aside. Mix up the order of the descriptions, and give each one a number from 1 to 12. Transfer these numbers to your copy for future reference.

Have each student write down his or her name and birthday on a piece of paper. Distribute the sheet with all the numbered (but otherwise unlabeled) horoscopes to the students and have them select the one description that best fits the day in question. (Be sure you remind them of the day the horoscopes apply.)

Ask the students to predict how they think this experiment will turn out. To prevent sudden changes of answers, ask students to exchange papers at this point. Then put the signs and birthdates associated with each numbered paragraph on the board. Have the class count how many students picked their own sign among the 12 and how many did not.

If Sun sign astrology predicts one's day pretty well and everyone remembers the day in question clearly (the astrologer's hypothesis), students should in general be able to find their own paragraph. But if chance instead of the stars governs the composition of those descriptions (the skeptic's hypothesis), we would expect that only one out of 12 of the students would have selected the description for their own signs.

Warning: With small numbers of students in one class, it often happens by chance that there are a few more correct picks than one would expect by chance. With older students, this can give you a chance to discuss the need for large samples in good statistical studies. If students get intrigued by such extra hits, one way to check is to extend the test to other students or school staff.