Game Development Reference
In-Depth Information
presses dispensed, they were setting prices for the liquid, that is, how much bang the
rats were getting for their buck.
After some time learning how the levers worked, the rats had a pretty good
handle on how much liquid was dispensed by each one. Invariably, they would
head for the one that gave them the most liquid. This doesn't seem important in
and of itself. In fact, even without a lever-press limit, we can all see that it would
make sense to patronize the establishment that was dishing out the most liquid.
Root Beer for Rats
The next change, however, gave the rats something a bit more complicated to pon-
der in their quest for quenching their thirst. The experimenters modified the box so
that one lever produced root beer—apparently a favorite beverage of lab rats—and
the other one dished out water flavored with quinine. Since rats do not seem to
appreciate the bitter taste of tonic water, it made for an appropriate counterpoint
to the tasty root beer. All other things being equal, a rat would choose root beer
over quinine. However, not all other things were equal!
The dispensers were set so that the amount of root beer provided was signifi-
cantly less than the amount of quinine. Again, without a limit on lever presses, this
decision is only slightly more complex. If you are a rat willing to work for it, the
root beer is still available to you… you just have to press more often to get it.
However, the researchers
did
set a maximum number of times that you could press
the two levers during a single session. (Note that this was
total
lever presses—each
lever counted against the single total.) With that limit in place (your fixed income),
however, you now have to decide how to spend wisely.
Enter the final criteria… you are a rat who gets thirsty—more thirsty than you
can satisfy by simply selecting the small doses of root beer. You are going to have to
satisfy your thirst with some combination of quinine and root beer. And
that
is what
gives us our decision to make. How much quinine should we put up with when we
really would prefer root beer?
Over time, the rats would work out a balance that satisfied both their individ-
ual levels of thirst and their preferences for root beer relative to quinine. For each
rat, there would be a slightly different level. In the end, however, equilibrium would
be established. They learned that they would have to quench much of their thirst
with the quinine and only occasionally dip into the root beer for a marvelous taste
holiday.
Again, that the rats established an equilibrium that balanced their desires is not
a surprise. The math is similar to that of purchasing the warranty, selecting work-
ers based on productivity, and deciding which goal is the most important when you
consider how long it takes to get there. The calculation is intuitive for the most part.
