# Of 2 Minds: How Fast and Slow Thinking Shape Perception and Choice [Excerpt]

In psychologist Daniel Kahneman's recent book, he reveals the dual systems of your brain, their pitfalls and their power

Why call them System 1 and System 2 rather than the more descriptive “automatic system” and “effortful system”? The reason is simple: “Automatic system” takes longer to say than “System 1” and therefore takes more space in your working memory. This matters, because anything that occupies your working memory reduces your ability to think. You should treat “System 1” and “System 2” as nicknames, like Bob and Joe, identifying characters that you will get to know over the course of this book. The fictitious systems make it easier for me to think about judgment and choice, and will make it easier for you to understand what I say.

SPEAKING OF SYSTEM 1 AND SYSTEM 2

“He had an impression, but some of his impressions are illusions.”

“This was a pure System 1 response. She reacted to the threat before she recognized it.”

“This is your System 1 talking. Slow down and let your System 2 take control.”

View
1. 1. Asteroid Miner 08:43 AM 6/16/12

There is a problem with the figures. I see only a little blue square.

2. 2. kered 09:30 AM 6/16/12

Excellent article, but would be MUCH better if we could see the pictures. EDITOR... please reformat so we can read easily... Using system 1 for the pics!!!!!!

3. 3. mike_midwest 02:33 PM 6/17/12

17x24 = 17x3x8 = 51x8 = (50+1)x8 = 400+8 = 408.

4. 4. HdeJong 04:30 PM 6/17/12

(16+1)*25-17 = 425-17 = 408

5. 5. kered 07:27 PM 6/17/12

hard math... try this way
17*24= 20*24-3*24 = 480-72=408
I am out of practice, took me ~~30 mins to figure this out... Whatever way, System 2, as System 1 cannot do these!!! Great article

6. 6. hugoal 06:31 AM 6/18/12

Try this way:
17*24=10*24+(10-3)*24=240+(240-72)=240+168=408
or this one that's even easier:
17*24=(10+10/2+2)*24=10*24+(10*24)/2+2*24=240+240/2+48=240+120+48=408
Great article.

7. 7. euroflycars 04:15 PM 6/18/12

Try that way:

17*2=34 --> 17*20=340
17*4=68

340+68=408

It's opportunistic, but that's why clever calculators will do it almost intuitively with their system 1.

8. 8. GeorgeOckel 05:24 PM 6/20/12

Article seems interesting but without pictures loses appeal

9. 9. craigc0 03:48 PM 8/7/12

needs the pictures. This has been noted many times, but no response.

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Click one of the buttons below to register using an existing Social Account.

## More from Scientific American

• News | 1 hour ago

### Shooting the Wheeze: Whooping Cough Vaccine Falls Short of Previous Shotâ€™s Protection

• Guest Blog | 1 hour ago

### Dissecting the controversy about early psychological response to disasters and trauma

• Ask the Experts | 6 hours ago | 1

### What Role Does Climate Change Play in Tornadoes?

• Reuters | 6 hours ago

• Reuters | 6 hours ago

More »

## Latest from SA Blog Network

• ### Dissecting the controversy about early psychological response to disasters and trauma

Guest Blog | 1 hour ago
• ### Why Are Barns Red?

Image of the Week | 1 hour ago
• ### The SciArt Buzz: ScienceArt On Exhibit In May/June 2013

Symbiartic | 3 hours ago
• ### Physics, Metaphysics and Cosmology Collide in New E-Book, Possibilities in Parallel: Seeking the Multiverse

STAFF
@ScientificAmerican | 3 hours ago
• ### My Heart is in Oklahoma now #OklahomaStrong

The Urban Scientist | 4 hours ago

## Science Jobs of the Week

Of 2 Minds: How Fast and Slow Thinking Shape Perception and Choice [Excerpt]

X

### Subscribe Today

Save 66% off the cover price and get a free gift!

X

X

###### Welcome, . Do you have an existing ScientificAmerican.com account?

No, I would like to create a new account with my profile information.

X

Are you sure?

X