Clifford Nass

Machines and Mindlessness: Social Responses to Computers

Following Langer (1992), this article reviews a series of experimental studiesthat demonstrate that individuals mindlessly apply social rules and expecta-tions to computers. The first set of studies illustrates how individuals overusehuman social categories, applying gender stereotypes to computers and ethnicallyidentifying with computer agents. The second set demonstrates that people exhibitoverlearned social behaviors such as politeness and reciprocity toward comput-ers.Inthethirdsetofstudies,prematurecognitivecommitmentsaredemonstrated:Aspecialisttelevisionsetisperceivedasprovidingbettercontentthanageneralisttelevision set. A final series of studies demonstrates the depth of social responseswith respect to computer “personality.” Alternative explanations for these find -ings, such as anthropomorphism and intentional social responses, cannot explainthe results. We conclude with an agenda for future research.Computer users approach the personal computer in many different ways.Experienced word processors move smoothly from keyboard to mouse to menu,mixing prose and commands to the computer automatically; the distinctionbetween the hand and the tool blurs (Heidegger, 1977; Winograd & Flores, 1987).Novices cautiously strike each key, fearing that one false move will initiate anuncontrollable series of unwanted events. Game players view computers as

Cognitive control in media multitaskers

Chronic media multitasking is quickly becoming ubiquitous, although processing multiple incoming streams of information is considered a challenge for human cognition. A series of experiments addressed whether there are systematic differences in information processing styles between chronically heavy and light media multitaskers. A trait media multitasking index was developed to identify groups of heavy and light media multitaskers. These two groups were then compared along established cognitive control dimensions. Results showed that heavy media multitaskers are more susceptible to interference from irrelevant environmental stimuli and from irrelevant representations in memory. This led to the surprising result that heavy media multitaskers performed worse on a test of task-switching ability, likely due to reduced ability to filter out interference from the irrelevant task set. These results demonstrate that media multitasking, a rapidly growing societal trend, is associated with a distinct approach to fundamental information processing.

Computers are social actors

This paper presents a new experimental paradigm for the study of human-computer interaction, Five experiments provide evidence that individuals’ interactions with computers are fundamentally social. The studies show that social responses to computers are not the result of conscious beliefs that computers are human or human-like. Moreover, such behaviors do not result from users’ ignorance or from psychological or social dysfunctions, nor from a belief that subjects are interacting with programmers. Rather, social responses to computers are commonplace and easy to generate. The results reported here present numerous and unprecedented hypotheses, unexpected implications for design, new approaches to usability testing, and direct methods for verii3cation.

Can computers be teammates

This study investigated the claim that humans will readily form team relationships with computers. Drawing from the group dynamic literature in human-human interactions, a laboratory experiment (n=56) manipulated identity and interdependence to create team affiliation in a human-computer interaction. The data show that subjects who are told they are interdependent with the computer affiliate with the computer as a team. The data also show that the effects of being in a team with a computer are the same as the effects of being in a team with another human: subjects in the interdependence conditions perceived the computer to be more similar to themselves, saw themselves as more cooperative, were more open to influence from the computer, thought the information from the computer was of higher quality, found the information from the computer friendlier, and conformed more to the computers information. Subjects in the identity conditions showed neither team affiliation nor the effects of team affiliation.

Silicon sycophants

A laboratory experiment examines the claims that (1) humans are susceptible to flattery from computers and (2) the effects of flattery from computers are the same as the effects of flattery from humans. In a cooperative task with a computer, subjects (N=41) received one of three types of feedback from a computer: “sincere praise”, “flattery” (insincere praise) or “generic feedback”. Compared to generic-feedback subjects, flattery subjects reported more positive affect, better performance, more positive evaluations of the interaction and more positive regard for the computer, even though subjects knew that the flattery from the computer was simply noncontingent feedback. Subjects in the sincere praise condition responded similarly to those in the flattery condition. The study concludes that the effects of flattery from a computer can produce the same general effects as flattery from humans, as described in the psychology literature. These findings may suggest significant implications for the design of interactive technologies.

Source Orientation in Human-Computer Interaction Programmer, Networker, or Independent Social Actor

When individuals apply social rules and social expectations while working on a computer, are they directly interacting with the computer as an independent social actor or source (the CAS model), or are they orienting to an unseen programmer or imagined person in another room (the CAM model)? Two studies provide critical tests of these competing models. In Study 1, all participants were exposed to an identical interaction with computers. In one condition, participants were told that they were dealing with computers; in another, they were told that they were interacting with the software programmers. Consistent with the CAS model, there were significant differences between the two conditions. Study 2 performed a constructive replication of Study 1 by replacing the programmer with a hypothetical networker. Again, differences between the two conditions provide evidence that people respond to the computer as an independent source of information.

Does computer-generated speech manifest personality? an experimental test of similarity-attraction

This study examines whether people would interpret and respond to paralinguistic personality cues in computer-generated speech in the same way as they do human speech. Participants used a book-buying website and heard five book reviews in a 2 (synthesized voice personality: extrovert vs. introvert) by 2 (participant personality: extrovert vs. introvert) balanced, between-subjects experiment. Participants accurately recognized personality cues in TTS and showed strong similarity-attraction effects. Although the content was the same for all participants, when the personality of the computer voice matched their own personality: 1) participants regarded the computer voice as more attractive, credible, and informative; 2) the book review was evaluated more positively; 3) the reviewer was more attractive and credible; and 4) participants were more likely to buy the book. Match of user voice characteristics with TTS had no effect, confirming the social nature of the interaction. We discuss implications for HCI theory and design.

Speech interfaces from an evolutionary perspective

36 September 2000/Vol. 43, No. 9 COMMUNICATIONS OF THE ACM Similarly, the human head and brain are uniquely evolved to produce speech [4, 11]. Compared to other primates, humans have remarkably well-developed and controllable muscles around the lips and cheeks. Indeed, more of the motor cortex (particularly Broca’s area) is devoted to vocalization than to any other function, in sharp contrast to every other animal, including primates. Only homo sapiens can use the tongue, cheeks, and lips, together with the teeth, to produce 14 phonemes per second [11]; even the Neanderthals, who are known for having large brains and elaborate cultural and social behaviors, could not sustain speech due to the structure of their breathing apparatus [4]. Modern humans are also exquisitely tuned for speech recognition. Infants as young as one day old show relatively greater left hemisphere electrical activity to speech sounds and relatively greater right hemisphere activity to non-speech sounds [11]; by 22 days old, infants exhibit the adult tendency for right-ear (and left-brain-hemisphere) dominance for spoken sounds (regardless of language) and left-ear (and right-brain-hemisphere) dominance for music and other sounds [11]. Why is the fundamental and uniquely human propensity for speech so important in the design of How does the human brain react when confronted by a talking computer? Answers from psychological research and its design implications help define the limits of what computers should say and how they might say it. Clifford Nass and Li Gong

Anthropomorphism, agency, and ethopoeia: computers as social actors

Attempts to generate anthropomorphic responses to computers have been based on complex, agent-based interfaces. This study provides experimental evidence that minimal social cues can induce computer-literate individuals to use social rules-praise of others is more valid than praise of self, praise of others is friendlier than pmise of self, and criticism of others is less friendly than criticism of self—to evaluate the performance of computers. We also demonstrate that different voices are treated as distinct agents.

Social-Psychological Origins of Feelings of Presence: Creating Social Presence With Machine-Generated Voices

We demonstrate, via 2 experiments (N = 72 and N = 80) done in e-commerce contexts, that social responses to technology influence feelings of social presence. Users feel stronger social presence when they hear a computer-synthesized voice that manifests a personality that (a) is similar to the user (especially to the extrovert user) as compared to dissimilar, (b) is consistent with the texts personality, and (c) is extroverted as compared to introverted. We discuss various applications of these findings to the design of human-computer interfaces, as well as to the study of presence.