Former student and friend
Miranda has been putting me to the task in a long running exchange appended
to this post. I will address two
general questions she poses at various points in this and a subsequent
post.
First, if virtuous behavior is
selected for, then why does vicious behavior persist? Why are some of us still tempted to do
immoral things and why are some persons so inclined toward immorality that they
become tyrants?
I reply that selection works by
favoring traits that are reproductively fit within a distinct environmental
context. The usual term for this is a niche.
Several distinct sets of organisms may be found at different altitudes
on a mountain because temperature, moisture, etc., form distinct niches. Niches may be geographically separated or
they may overlap and more than one may be found inside another. An environmental niche will usually include
other organisms in such roles as predators and prey, mates and partners. Thus, in adapting to a niche one species will
often create a niche for another, as a large animal, in making a home in the
forest, makes a home for his load of parasites.
Finally, different individuals within the same species will sometimes
occupy slightly different niches. The
reproductive interests of male and female are rarely identical.
The simplest model for
understanding how distinct niches can favor both morality and immorality is the
infamous prisoner’s dilemma. This is a
simple game in which two players have each the choice to cooperate or
defect. Here is the payoff matrix:
The game produces a
paradox. In a single round, each player
does better by defecting regardless of what the other player does. In an extended series of rounds, both players
do better by cooperating. That is the
logic of justice.
In a famous tournament
involving computer programs that consisted of strategies for playing the game,
the most successful strategy was called Tit For Tat. This program always begins by cooperating and
then on each subsequent move it mimics what the other player did on the last
move. TFT wins by forming cooperative
partnerships with any player inclined to cooperate and by punishing defectors
(as well as limiting they damage they can inflict). TFT is the simple logic of righteousness in
exchanges. The unrighteous, always-defect
hawks fare poorly against a population of honest cooperators.
TFT also creates a niche for
the saintly, always-cooperate program, which prospers when it is playing with
TFT. However, this in turn creates a
niche for the occasional hawk who makes out like a bandit when he encounters a
saint.
Replace points with offspring
and this provides a model for the evolution of virtue. Honest cooperators are stronger,
collectively, that dishonest defectors.
However, the more successful that an honest community becomes, the more
it leaves a niche for the conman who can effectively exploit the trust that the
cooperators have achieved. That is why
most people are not very good at cheating and why no human community is free
from cheats.
Christopher Boehm argues in the
second chapter of Moral Origins that,
while our moral emotions keep us in check most of the time, the temptation to
cheat when we think we can get away with it is also selected for. This seems to me to be right.
