This is Hidden Brain.
I'm Shankar Vedantam.
There is a reasonable assumption we make as we go through life.
Groups act in their own self interest.
Merchants sell things in order to make money.
Employers want to hire the best employees.
Sports teams want to win matches.
The assumption of self interest is also the lens through which we understand how individuals behave.
We can see why someone might lie on a resume in order to get ahead.
We also know that no one would lie on their resume to make themselves look worse.
When people are accused of wrongdoing,
it makes perfect sense that the guilty would claim to be innocent.
But every ounce of common sense tells us no innocent person would ever confess to doing something wrong.
We understand as a matter of common sense and intuition that people behave in ways that favor their self interest.
How in God's name does that favor your self interest?
How and why people come to betray their self interest?
This week on Hidden Brain.
In the sixth grade, Saul Kassen received an assignment from his teacher to write a book report.
It took him about a nanosecond to decide to write about his hero, Mickey Mantle.
I was a huge Yankees fan, and I wanted to do a really good job.