Thinking and Deciding

446 SOCIAL DILEMMAS: COOPERATION VERSUS DEFECTION
Normative and prescriptive theory of social dilemmas
The problems caused by the existence of social dilemmas are among the most important
that human beings have to solve. If we could learn always to cooperate, wars
would disappear and prosperity would prevail. Even without achieving such a utopia,
more cooperation would solve many other human problems, from conflicts among
roommates and family members to problems of protecting the world environment.
These are problems for a prescriptive theory, a theory that takes into account ordinary
human behavior. It has been my approach throughout this book, however, to
stand back from the immediate problem and try to develop a set of standards that
we can apply to evaluate possible prescriptive solutions, that is, a normative theory.
Especially in a domain that is so full of prescriptive panaceas as this one — from
Marxist revolution to laissez-faire capitalism (at the national level of the problem)
— we need to know what makes a prescriptive theory good before we argue about
which one is best. We also need a descriptive account of human motives and behavior
in social dilemmas. We need to know where the problem is before we try to fix
it.
The problem of normative theory is especially difficult because of a clear conflict
between two different ways of applying utility theory. First, utility theory is
a normative theory of satisfying personal goals. Some of these goals are altruistic
(as we have noted throughout), but most of us have other goals that are purely selfish
and that sometimes conflict with the goals of others. Second, utility theory, in
the form of utilitarianism, has been applied as a normative theory of what is best
for everyone, a moral theory that treats all individual goals as equally important, no
matter whose goals they are. Because some goals are selfish, these two applications
of utility theory cannot give the same answer to every question about what we should
do.
To call attention to this conflict, which lies at the heart of the problem of normative
theory for social dilemmas, I shall, as an expositional device, discuss only
selfish goals. Clearly, if people are sufficiently altruistic, social dilemmas will disappear,
since there is no conflict between self and others, but we are not always so
altruistic, and that is when the problems arise.
We shall consider the three normative theories that are the obvious candidates for
the normative theory of social dilemmas. At the one extreme of altruism, we have
what I shall call the cooperative theory. Very close to this theory stands utilitarianism
itself. At the extreme of self-concern, we have what I shall call the self-interest
theory.
Let us consider these views in the context of a classic example: walking across
the lawn instead of on the sidewalk, in a public place. Suppose that everyone prefers
to have a nice lawn in front of the college library, but each of us can benefit (save
time) by taking a shortcut across the lawn. In this situation, “cooperation” can be
defined as staying on the sidewalk (avoiding the shortcut), so that the grass does
not get trampled to death. A few people could walk on the grass without killing it,
however. It takes a fair amount of traffic to kill the grass. If a lot of people have