Saturday, October 31, 2009

The Grapes of Greed

The Grapes of Greed - Sheva Apelbaum

I love grapes.  They are an amazing fruit, they come in clusters, and they’re sweet, crunchy, and pretty to look at to boot.   My mom usually buys them once a week and puts them out in a big bowl (she’s a potter).  I snack on them during the weekend, and my dad, who is also a grape fancier, joins me in the nibbling.  Between the two of us we can go through the entire bowl in a day or two.

Sometimes he tosses them at me at the table and I catch them mid-air, which is by itself amazing because I apparently do it with my eyes closed.

Today, as I was looking at my dad eating some grapes I noticed that he didn’t just pick them randomly.  He first  looked at the contents of the bowl, his hand floated in the air above them for a second or two, and then he picked one specific grape. 

On my next trip to the bowl, I caught myself doing the same thing my dad did.  I first looked at all the grapes and then reached for the one that looked the juiciest and most plump. After picking one, I repeated this process over and over again until there were no more grapes left.  So the interesting thing is that even though in the end we end up eating all of the grapes, we select them one at a time, always picking the one that looked the best.

I told my dad about my observation and he said that this process actually has a name. It’s called the Greedy Algorithm.  It turns out that its one of the most common programs we use for solving problems known as optimization.

I tried to think about other examples of how we choose an item from a collection and quickly came up with another favorite of mine—eating French fries.  I always start by picking the best looking ones (longest and fattest) first, and then I work my way down to the smallest ones until I’ve eaten them all. I do this even if I’m not sharing them with anybody else.

That’s the interesting thing, actually. Why spend all of this effort on sorting and picking each item when it would be faster to just eat them randomly?

Now that’s literally  food for thought.


  1. Dear grapecatcher!
    Now this is very interesting, because I do the exact same thing with cherries - they are my absolute favorite fruit and I alsways start eating them by picking the largest and most red ones - and I also will always finish off all of them. Never thought there could be some math behind it though! Funny I don't bother doing this with grapes - or maybe I do? I have to pay attention to this!
    Kol ha kavod to a smart girl!

  2. There could be an evolutionary reasoning behind it. Maybe in the past, our ancestors might have run out of time or were chased away by predators before finishing their meal on a bush of fruits or nuts. Thus, to promote maximum nutritional value, our minds instinctively seek out the most "valuable" fruits or nuts just in case we might lose access to them. This instinct can encompass all actions that we make promoting our minds to always make the best choice given the moment that we have be it choosing the largest grape or choosing the most attractive mate or going down the safest path as we never know if we will get a second chance. Greed is a powerful tool implemented into humans by nature and has allowed us to survive as long as we have.