Human brains are stupidIntuition, fallacies, paradoxes and biases

Why we have to be careful and the robots will win in the end anyway

1

We can stop if you get bored

24 slides, 10 things that will mess with your mindPartly based on this talk:

https://www.youtube.com/watch?v=7i-XjhGdCMU

2

Quick fire: left or right is larger?

3

2+4 1+3

4

2+4 1+3

5

6 letter words having "n" as 5th letter

6 letter words ending in "ing"

6

6 letter words having "n" as 5th letter

6 letter words ending in "ing"

7

Fishing rod on a bus● Luggage over 4ft isn't allowed on the bus● 5ft fishing rod

8

Fishing rod on a bus● Luggage over 4ft isn't allowed on the bus● 5ft fishing rod

9

Banzhaf power index● 3 stockholders: 49%, 49%, 2%● majority of 51% is needed● Who has the most power?

10

Banzhaf power index● 3 stockholders: 49%, 49%, 2%● majority of 51% is needed● Who has the most power?

● Each stockholder has equal power - any 2 can make a majority

11

Thinking 3 dimensionally● Sea level to mount everest (9000m) = 4 million pennies● What size box will they fit in?

12

Thinking 3 dimensionally● Sea level to mount everest (9000m) = 4 million pennies● What size box will they fit in?

● 2m x 2m x 2m

13

Thinking 3 dimensionally● all humans end to end = to moon and back 8 times● fit in Grand Canyon (446km long) in equal sized boxes

14

Thinking 3 dimensionally● to moon and back 8 times = all humans end to end● fit in Grand Canyon (446 km long) in equal sized boxes

● 7m x 7m x 7m

15

Bus race!● Bus does the 1st 1/2 of the route at 15mph● What speed should they do the other 1/2 to average 30mph overall?

16

Bus race!● Bus does the 1st 1/2 of the route at 15mph● What speed should they do the other 1/2 to average 30mph overall?

● ∞

17

Statistics!● Death rate in Navy in Spanish-American War in 1898 is 9/1000● Civilians 16/1000● Propaganda: Safer to be in Navy?!

18

Statistics!● Death rate in Navy in Spanish-American War 1898 is 9/1000● Civilians 16/1000● Propaganda: Safer to be in Navy?!

● Cannot compare groups. Navy = young, healthy people

19

Survivorship bias● WW2: add armour to bombers● Stats show most planes came back with damage from bullets on the wings● Conclusion: add thicker armour on the wings

20

Survivorship bias● WW2: add armour to bombers● Stats show most planes came back with damage from bullets on the wings● Conclusion: add thicker armour on the wings

● No!● Bombers hit in the cockpit never came back● Add armour around the cockpit

21

Expectation bias● When you get the result you want, you stop experimenting

22

Simpson's paradox● Ticket sale conversions A/B test

iOS Android

Control 1400/4000 = 0.35 200/1000 = 0.2

Experiment 40/100 = 0.4 22/100 = 0.22

23

Simpson's paradox● Ticket sale conversions A/B test

iOS Android Total

Control 1400/4000 = 0.35 200/1000 = 0.2 1600/5000 = 0.32

Experiment 40/100 = 0.4 22/100 = 0.22 62/200 = 0.31

24