## RS58 - Intuition

Release date: April 8, 2012

When your intuition tells you something, should you listen? That depends! Relying on intuition can be anything from a highly effective strategy used by experts, to an excuse not to require evidence for your beliefs. In this episode, Massimo and Julia talk about what people mean by "intuition," where our intuitions come from, and when intuition can beat careful reasoning.

*Julia's pick: "Information is Beautiful - Snake Oil?"*

*Massimo's pick:*

*"Zombie Economics: How Dead Ideas Still Walk among Us"**References:*

*http://measureofdoubt.com/2011/11/14/what-do-philosophers-think-about-intuition/ *

## Reader Comments (9)

Hi,

I really enjoy your podcast. I was wondering if you could clarify something from this episode?

Julia discussed the failure to take into account the background rate when interpreting some statistics. So if a rare disease has a background rate of 1/1000 in the general population, and a test that has a false positive rate of 5%, and you test positive, it is still unlikely that you have the disease.

I remember learning about this in my statistics class all those years ago, but I cannot remember how to do the math! I was wondering if you could briefly explain it? Or point me in the right direction of where to find out about it? (A quick google search didn't help me, mostly because I don't know the right search terms to use). It's a really neat demonstration of how statistics aren't intuitive, I just wish I could remember how to arrive at the right answer!

Thanks!

Ok, I found what I was looking for above. If anyone else is looking for it, there is a good description at: http://www.cs.ubc.ca/~murphyk/Bayes/bayesrule.html

Hi Ed, you can find a faitly thourough explanation with examples on the wikipedia page here: http://en.wikipedia.org/wiki/Base_rate_fallacy

Thanks Gil!

re: 10,000 hours and expertise

If you haven't heard about The Dan Plan you might find it interesting. A guy with no golf experience quit his job so that he could spend 10000 hours practicing golf to try and become a professional golfer. He's about 2500 hours in.

http://www.thedanplan.com/

When you do enough statistics problems, it becomes intuitive. Take the base rate 1/1000, multiply by the true positive rate over the false positive rate, say 95/5, and you get the approximate probability after testing positive. To get the exact answer, use odds instead of probabilities, e.g. 1/999 instead of 1/1000.

There are some studies related to gut-instinct intuition vs rationale when donating money to causes. I only remember hearing about a couple, but one study compared donation rates to help protect panda habitat. Two approaches were used: presenting possible doners with simple graphs and factual information that explained the problem, or mainly showing cute pictures of pandas. The second approach got more people to donate, but they only gave small amounts of money. When people's critical thinking was engaged, more money was raised on average (people seemed to be donating in proportion to the problem). That was just one study but this podcast reminded me of it.

Talent usually does occur in people who take up a particular skill at an early age.

For the bat and ball question, people with a really strong background in STEM disciplines tend to actually intuitively apply mental algebra to the problem, and start calculation with the formula x + y = 110, y= x + 100, 2x + 100 = 110, therefore x = 5, y = 105. Thus STEM people probably got this question correct a lot more often than humanities and arts people. However, just intuitively applying a formula can lead to errors as well. In other words, a system 1 Intuitive response may direct you to a previous correct system 2 deliberative response, but could also misdirect you to a previous system 2 deliberative response that fails to produce the correct answer to the present challenge. Every good scientist and engineer knows to carefully analyze the particular circumstances of a problem before just plugging in values to a formula.

Asking someone to cut in line because, "I need to make copies" does in fact let someone know that you want to cut in line due to a need, however obvious, instead of just a disrespect for the person in front of you, or that you simply want to disregard the general social rule of waiting your turn. It also implies the additional statement "and I'm pressed for time right now", even if not expressly said.

All of the supplements have precious little validity for providing health benefits. Taking a daily standard multivitamin and multimineral tablet, getting enough omega 3 and 6 oils, eating enough protein, and eating the correct amount of calories does have a definite benefit. For a person who has some serious deficiency such as B-12 malabsorption syndrome, or vitamin D deficiency, supplements of these do have definite benefits, but otherwise taking mega doses of ANY of these vitamins, minerals, and herbs has absolutely NO real health benefit. Vitamins and Minerals generally work as cofactors for enzymes in the body, so once you take your RDA, assuming you have normal absorption of the substance, you more than saturate all the enzymes with the vitamin or mineral and achieve maximal catalytic efficiency. The government calculates the RDA to exceed what you probably need to thrive.

St John's Wort and Coffee may have some actual pharmaceutical substances in them. This turned out to be true with South American tree bark (Salicylic Acid - Aspirin) and English Witch's Brew (Digitalis). We expect that a lot of Chinese, Indian, and other traditional herbal medicines will eventually reveal lots of other genuine pharmaceutical agents.

informationisbeautiful.net has a ton of really kool information on it !! Thank you.