Manipulation 393peek at the hard-to-find commodity. By the same token, after
the censorship or prohibition is lifted, interest in the object in
question tends to wane.
Surprisingly, there is a paucity of research on the psychol-
ogy of scarcity. The enhanced desirability of scarce items
may reflect a perceived loss of freedom to attain the items, in
line with reactance theory. The censorship example certainly
suggests that people value an object in proportion to the in-
junction against having it. People don’t like having their free-
dom threatened, and making an item difficult to obtain or
forbidding an activity clearly restricts people’s options with
respect to the item and the activity. Reactance is a reasonable
model, but one can envision other theoretical contenders.
Simple supply-and-demand economics, for example, has a
direct connection to the scarcity phenomenon. The lower the
supply-demand ratio with respect to almost any item, the
more those who control the resource can jack up the price and
still count on willing customers. Perhaps there are viable evo-
lutionary reasons for the heightened interest in scarce re-
sources. The conditions under which we evolved were harsh
and uncertain, after all, and there may have been selection
pressures favoring our hominid ancestors who were success-
ful at securing and hording valuable but limited food supplies
and other resources.
Yet another possibility centers on people’s simultaneous
desires to belong and to individuate themselves from the
groups to which they belong (e.g., Brewer, 1991). Scarcity
has a way of focusing collective attention on a particular ob-
ject, and there may be a sense of social connectedness in
sharing the fascination with others. Waiting in line with
throngs of shoppers hoping to secure one of the limited
copies of the latest Harry Potter volume, for example, is ar-
guably an annoying and irrational experience, but it does
make the person feel as though he or she is on the same wave-
length as people who would otherwise be considered total
strangers. At the same time, if the person is one of the lucky
few who manages to secure a copy before the shelves are
cleared, he or she has effectively individuated him- or herself
from the masses. In essence, influence appeals based on
scarcity may be effective because they provide a way for peo-
ple to belong to and yet stand out from the crowd in a world
where he or she may routinely feel both alienated and
homogenized.
Manipulation Through Norms
Human behavior, compliance included, is driven to a large
extent by social norms—context-dependent standards of be-
havior that exert psychological pressure toward conformity.
At the group level, norms provide continuity, stability, and
coordination of behavior among individuals. At the individ-
ual level, norms provide a moral compass for deciding how to
behave in situations that might offer a number of action alter-
natives. The norm of social responsibility (e.g., Berkowitz &
Daniels, 1964), for example, compels us to help those less
fortunate than ourselves, and the norm of equity prevents us
from claiming excessive compensation for minimal contribu-
tion to a group task (cf. Berkowitz & Walster, 1976). Norms
pervade social life, and thus provide raw material for social
influence agents. By tapping into agreed-upon and internal-
ized rules for behavior, those who are so inclined can extract
costly commitments to behavior from prospective targets
without having to flatter them.The Norm of ReciprocityThe obligation to repay what others provide us appears to be
a universal and defining feature of social life. All human so-
cieties subscribe to the norm of reciprocity(Gouldner, 1960),
which is understandable in light of the norm’s adaptive value
(Axelrod, 1984). The sense of future obligation engendered
by this norm promotes and maintains both personal and for-
mal relationships. And when widely embraced by people as a
shared standard, the reciprocity norm lends predictability, in-
terpersonal trust, and stability to the larger social system.
Transactions involving tangible assets are only a subset of the
social interactions regulated by reciprocity. Favors and invi-
tations are returned, Christmas cards are sent to those who
send them, and compliments are rarely accepted without find-
ing something nice to say in return (Cialdini, 2001).
The social obligation that there be a give for every take is
well-documented (DePaulo, Brittingham, & Kaiser, 1983;
Eisenberger, Cotterell, & Marvel, 1987; Regan, 1971). Even
when gifts and favors are unsolicited (or unwanted), the re-
cipient feels compelled to provide something in return. The
ability of uninvited gifts to produce feelings of obligation in
the recipient is successfully exploited by many organizations,
both charitable and commercial. People may not need per-
sonalized address labels, key rings, or hackneyed Christmas
cards, but after they have been received, it is difficult not to
respond to the organization’s request for a “modest contribu-
tion” (e.g., Berry & Kanouse, 1987; Smolowe, 1990). A par-
ticularly vivid example of this tendency is provided by the
Hare Krishna Society (Cialdini, 2001). The members of this
religious sect found that they could dramatically increase the
success of their solicitations in airports simply by giving trav-
elers a free flower before asking for donations. People find it
hard to turn down a request for money after receiving an un-
solicited gift, even something as irrelevant to one’s current
needs as a flower. That receiving a flower is not exactly the