Status: work-in-progress - 30% complete
Last modified: 2016-11-03

The Feast Table Model


Is there any difference between intrinsic rewards – those that a person defines and administers for themselves – and extrinsic rewards – those that come from some other person, organization, or institution?

Much of Economics, Game Theory, and Public Policy modeling the interests of actors using a generalized/aggregate subjective utility metric. In this model, there is no meaningful difference between intrinsict and extrinsic. This leads to interventions and improvement prescriptions that heavily rely on extrinsic incentives.

This chapter explores this question about intrinsic and extrinsic rewards using a model of situational social + cognitive processes which I will nickname “The Feasting Table” model, for reasons that become immediately obvious.


Imagine that you are at a big feast (e.g. Thanksgiving in the US) where food is served communally. The norms of service are roughly: Each person picks up the nearest serving dish or platter, takes some food if they want, then passes the dish to someone next to them. Often, by habit or by declaration, the food dishes are passed in one direction. Often, people make pleasant comments about the dishes as they arrive – “Ooh, this looks good!” – and other people might make comments like “Yes, it is. I’ve tried it.” or “Save me some of that!” or “What is it?”. If the diners also made some or all of the food, people pay and receive complements to the chefs as the food is passed.

We modify the feast norms this way:

  1. Every participant in the Feast is an Actor, i.e. an agent in a role with purposeful functions. Each Actor has some degree of pride in their own choices and preferences, relative to how much they defer to others.

  2. Every Actor starts with food (“my food”) on their own plate which they selected (and perhaps made). “My food” represent the intrinsic rewards for each Actor. The “my foods” for Actors may of the same type (e.g. “stuffing”) but they will always be distinct in detail (seasoning, cooking style, non-allergenic, vegan, etc.).
  3. Some number of communal plates go around, some empty initially and some pre-loaded with a type of food not associated with any Actor. These “other foods” represent extrinsic rewards for any Actor.
  4. Whenever a communal dish arrives, the Actor has the choice to:
    1. Take some food off of the communal plate and/or
    2. Put some food from their own plate on to the communal plate
  5. They can see what Actors are doing (taking or giving) and can also send or receive signal or messages to other Actors.
  6. Last, whenever any Actor puts food on to a communal plate, they can (optionally) “tag it”, which is the act of saying the name of the Actor or the type of Actor for whom this food is intended. (Thus, as a single communal plate goes around, it may acquire many such intentional tags: e.g. “The blue mashed potatoes are for the kids”, “The turkey wing is for Alice”, and so on). Re-transmitting tags is noisy, in large part due to reinterpretation by each Actor in the chain (like the game “Telephone”).

In the end, “eating” is behavior that the food is rewarding, though there is also the social reward for being a good member of the Feast:

  1. For themselves: Get enough of the food types that you want/like.
    1. If you don’t like any of their food, you don’t have to eat it.
    2. Mostly honor your “my food” choice, as place of pride
  2. For themselves as members of the Feast: be a good member and help make it a good Feast for everyone. For example:
    1. Don’t waste any food, if possible.
    2. Don’t take food tagged for someone else
    3. Maybe be generous with your “my food” if other Agents might want/need it
    4. (and so on)

Crucially, there is an asymmetric relationship between “my food” and “other food”. Each Actor selected (and perhaps made) their “my food” specific to their prior preferences, constraints, habits, and norms about what they would like for themselves. Each Actor is thereby somewhat attached to “my food” – that is what makes it mine.

In contrast, they will initially have much more limited information about “other food”. Actors may ask themselves: “It may look familiar but is it?” “Was it properly cooked and (therefore) safe to eat?” “Will it violate any of my eating restrictions?” and so on.

Notice the social mechanism: What will other Actors think of me if they see me eating X or not eating Y? Will they see me as a “good member” or not? This social mechanism and associated interest is also an extrinsic reward, but it a “public good” – collective and non-rival* – in contrast to the “my + other food” on each Actor’s plate, which are “private goods” by the time the eating starts.

*"Non-rival" means that if one Actor "consumes" a public good, it doesn't diminish the value or availablilty for any other Actor. Beautiful natural scenary is a collective non-rival public good. The reverse is true for private goods, which are rivalrous.

Regimes of System Behavior

There are a number of regimes of behavior that we might expect to see. One is To each His Own, where every Actor only eats their “my food”, doesn’t share with others and doesn’t take any communal food. Another (the opposite) is Anything but My Own, where every Actor gives away their “my food” and eats only “other food”. Another is “One Chef to Rule Them All”, where one Actor brings enough food for everyone and tries to impose it on everyone else. If their “my food” is both abundant and sufficently better for all Actors, the One Chef might just succeed.

The regimes we are most interested are in between these extremes, where each Actor ends up with a combination of “my food” and “other food”, and their personal mix affects which food is passed in communal dishes, and how receptive each Actor is to “other food” given their current endowment of “my + other food” (a.k.a. mixture of intrinsic and extrinsic rewards). This will be especially interesting when “my food” clashes with “other food” (savory vs. sweet, or even more extreme).


[To Do]