Swiss author Rolf Dobelli wants to save us all from the logical errors that humans have been making for generations.

Swiss author Rolf Dobelli wants to save us all from the logical errors that humans have been making for generations.

His new book, "The Art of Thinking Clearly," is a fast-paced, engaging examination of dozens of mental traps that lead us to make bad decisions.

Dobelli first began compiling lists of cognitive errors for his own use, then began writing a weekly newspaper column that eventually led to his book.

"The Art of Thinking Clearly" is broken down into bite-sized, three-page chapters that are surprisingly addictive, a bit like a bowl of M&Ms. But instead of eating candy-coated chocolate, the reader is happily ingesting terms such as "sunk cost fallacy" and "neglect of probability."

People fall prey to the sunk cost fallacy when they stick with an unpleasant or costly situation simply because they've invested so much time, energy or money into it.

If you paid to watch a movie, find out it's terrible but continue to sit in the theater, you are not only wasting the money spent on the ticket, but your time.

Assess only the future costs and benefits of your decision, not the sunk costs, when deciding whether to continue on or pull the plug, Dobelli advises in his book.

That way, you can walk away from bad movies, bad relationships and bad investments.

Dobelli warns about the confirmation bias, which causes people to embrace information that buttresses their existing beliefs, while screening out information that challenges those beliefs.

He recommends writing down our beliefs, then purposefully setting out to find information that challenges our assumptions.

We like to stick to our beliefs, and we also like to believe that we are knowledgeable and skilled. This leads to the overconfidence effect.

In one survey, 93 percent of students rated themselves as "above average" drivers — impossible, since only a minority can be above average.

A related logical error, self-serving bias, causes people to overestimate their contributions, whether they are coworkers, roommates or married couples.

Dobelli separately asked five roommates how often each took out the trash. The average response should have been 20 percent of the time, adding up to 100 percent.

Instead, each roommate was convinced he took out the trash quite often, and the total percentage added up to 320.

People not only overrate their contributions, but they also tend to slack off the bigger a group gets.

An engineer had several men pull individually on a rope and he measured their power. If two men pulled together, they invested 93 percent of the power they had used when pulling individually. When eight men pulled together, they used just 49 percent of their individual power.

It's OK to have people work together in teams, but leaders should figure out ways to measure each person's individual contributions, Dobelli recommends.

As a reporter, I often run into people caught up in the introspection illusion, which causes people who have reflected on an issue to believe that their views represent the truth.

People who believe their views are the truth only have three reactions to people who don't share those views, Dobelli notes.

They think that the person with the opposing view is either ignorant of the facts, just plain stupid or evil.To counter the introspection illusion, Dobelli advises, "Be all the more critical with yourself. Regard your own internal observations with the same skepticism as claims from some random person."

Reach reporter Vickie Aldous at 541-479-8199 or