Nonverbal Behaviors, Personality, and Motivation
Nonverbal behaviors, especially gaze, have long been recognized
in social-sciences literature as useful tools in persuading
others to comply with requests or demands. A number of theories
have been proposed to explain this phenomenon, including
speech accommodation theory, demand theory, and arousal
intimacy theory [40]. According to speech accommodation
theory, people may change their communication behaviors
when interacting with others and convergence toward the style
of the partner should produce a positive attitude in the partner
and thus lead to compliance. According to demand theory,
nonverbal behaviors can function as demands (e.g., staring as
a demand for a response), producing a level of arousal that
targets can alleviate by complying with any implicit or explicit
demands. In arousal intimacy theory, nonverbal behaviors are
predicted to produce compliance because they produce greater
perceptions of intimacy between the source and target, leading
to compliance when the target experiences positive arousal.
Each of these three theories predicts a strong relationship
between nonverbal behaviors and compliance.
A large amount of previous research has empirically demonstrated
the positive effect of gaze on compliance. When a
collector of money for charity engaged in mutual gaze with
possible donors, rather than looking at the collecting tin, they
were more successful in receiving donations [4]. Nonverbal
behavioral cues, such as gaze, gesture, and proxemics, are
sometimes referred to as immediacy cues [6]. Students are
more likely to comply when they perceive their teachers as
moderately to highly immediate, and are more likely to choose
to reject requests made by nonimmediate teachers [5]. Similarly,
attraction and dominance increase compliance and cues
of such are often expressed through nonverbal cues like gaze
[34]. Gaze is also closely tied to personality, with extroverts
commonly engaging in significantly more mutual gaze with
their conversational partners than do introverts [37].
In addition to nonverbal behaviors and personality, attempts
to increase compliance in others must take into account a person’s
motivation, which can vary not only in magnitude but
also in orientation [38]. The most basic distinction in motivation
orientation is between intrinsic, which refers to doing
something because it is inherently interesting or enjoyable,
and extrinsic, which refers to doing something because it is accompanied by external pressure or control. In the current
work, we use socially assistive robots to create extrinsic motivation
in users, but also take into consideration the intrinsic
motivation that those users have to complete the task.