What was the issue of the debate?
Who was right?
Where did you learn this?

Answers of CSUF Intro. Psych
Students (high school grads)

80% Say that the issue was the

SHAPE of the earth.
They say Columbus said it was ROUND
 and the scholars said it was FLAT.
They say Columbus was right.

Most say they learned it in school.

Answers by College Students:

About 10% say the issue was whether there was NEW LAND to be discovered

About 9% say they don’t know or give
 other wrong answers.
About 1% say that the issue was the
SIZE of the earth (correct answer).

The Correct Answer: SIZE




Both Columbus and scholars agreed the world was a sphere. That was settled for more than 2000 years.
The debate was about the SIZE of the earth.
Columbus said that India was only about 2500 miles west of Spain.
He was off by >10,000 miles.
Scholars knew the earth was about 25,000 miles in circumference.

Eratosthenes (276-195 BC)

Inventor of “geography”, latitude and longitude, he estimated the size of the earth from geometric measurements.

His estimate was much more accurate than

Columbus’s (1700 years later).
The scholars knew of his estimate and concluded that Columbus’ trip would be too far for wind-powered ships, given the amount of water and food needed.

Columbus was Lucky

Neither the scholars nor Columbus knew
 about the “New” World.
Columbus found land where he expected and thought he got to “India”. He called the people “Indians”. Some still do.

Later, this land named “America”.

Wrong Information is Hard to
Correct

Students bring wrong information
 with them and find it hard to unlearn.
Only about 50% of the class revises their beliefs concerning this question after a lecture on it.

Illustrates the power of wrong ideas.

Following a College Lecture…

About 50% now say the issue was SIZE of
 earth (what they were told).
About 25% continue to say SHAPE;

About 25% give other wrong answers:

“He wanted to find the “West Indies” by
 sailing East (learned in history 110B)”
“They were arguing over who discovered

America”
“Did he have enough money for the voyage?”

Why Present This to Students?

The lesson is presented to illustrate how people bring wrong information with them to school…

And to illustrate that it is hard to
 correct wrong information.
Psychology is a subject with lots of wrong information in the media.