Technological insularity is defined as a psychological construct associated with technology-mediated communication in which the communicator is more isolated from and less mindful of the recipients or intended audience when engaged in computer-mediated communications than when engaged in face-to-face conversations. The development and administration of a scale, the 'Technological Insularity Scale,' or 'TIS,' which measures the construct 'technological insularity,' is explained here. The psychometric quality of the TIS is supported by results of a factor analysis, and relationships found between the scale and social desirability, empathy, and social isolation scales. This study contributes the understanding of technology's implications for personal and societal behavior. Implications for theory and research are discussed.