Wednesday, January 27, 2021

the stamford marshmallow experiment and בוצינא טב מקרא

The famous Stamford marshmallow studies "found that children who, as 4-year-olds, could resist a tempting marshmallow placed in front of them, and instead hold out for a larger reward in the future (two marshmallows), became adults who were more likely to finish college and earn higher incomes, and were less likely to become overweight."  

In other words, the ability to delay gratification, to hold out for a larger reward, is the key to success.

Kesubos 83b:

אמר אביי בוצינא טב מקרא

Rashi: וצינא טב מקרא. בוצינא דלעת קטנה קרא דלעת גדולה והאומר לחבירו קח לך דלעת קטנה בגינתי או המתן עד שיגדילו וקח גדולה טוב לו ליקח הקטנה מיד כי לא ידע מה יולד יום

Is Abayei saying that it is better to take the one marshmallow up front? 

Or is Abayei just telling us what more people do, not necessarily the best thing to do?

Or maybe Abayei has nothing to do with the marshmallow experiment?  Maybe you  can be mechaleik and say that there is a lot more risk involved in growing a plant than in waiting for someone to come back in a few minutes with that extra marshmallow.  I don't know whether a four year old would perceive it that way.  Why should he/she trust an unknown person making a promise?  

The marshmallow experiment has been generalized to other, more risky situations, as well.  For example, if you own a stock and the share price has gone up, do you sell, or do you hold out for better returns?  It seems to me that Abayei would council to sell and lock in your earnings now rather than delay and risk losing what you have.  However, do a search on stock price and marshmallow test and you will find lots of folks who invoke the marshmallow experiment to council holding out for the greater gains e.g. here, here, here.

3 comments:

  1. one in the hand is better than two in the bush - that's how I understand that statement of Abayei -I think that it s different from the marshmallow case where you ודאי get more vs. where it is a ספק - which may be more comporable to stocks, but there are many variables there, see also https://www.psychologytoday.com/us/blog/hide-and-seek/201703/is-bird-in-the-hand-worth-two-in-the-bush

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  2. I think the point of the Marshmallow Test is that it is on kids who are too young to perceive promises by adult authority figures as risky. In their worldview, they are being asked to choose between two certainties -- two marshmallows later, not a likelihood of getting two marshmallows later.

    In terms of Wall Street, prices are probability of an outcome times payout for that outcome, summed across all possible outcomes. (To get a little more complicated, you have discount the value because you're not getting the payout now but later. After all, you could have instead bought something basically risk-free, like a government bond, and end up with the same money So it's really only worth however much your risk-free investment would cost you now to get the same expected payout.)

    So, the investor's answer would be: If your probability of catching more than one bird is greater than the probability of not catching either, AND you cannot invest the bird in your hand in the time the hunting would take you to make enough to buy the same fraction of a second bird as that probability -- the two birds in the bush are better.

    Straight expected value calculations from statistics 101.

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  3. -- pots of meat "in front of them", 16:3, versus a milk-and-honey dream "reward in the future";


    -- "marshmallow experiment", part 2

    place two marshmallows out, 'to last for two days'. can the child resist the second glob on day one?

    those who searched for mon at netz, 16:27, had binged on the double-portion Friday night, leaving none for the morrow...


    Label: beshalach

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