This dissertation work considers communication between people. I look at coordinating dyads (couples in relationships) and people in working relationships to develop an understanding of how people engage in high-stakes, or emotional communication via various communicative media. The approach for this research is to observe and measure people's behavior during interaction and subsequent reporting of that behavior and associated internal experiences. Qualitative and quantitative methods are employed. Quantitative data are analyzed using a range of statistical analyses, including correlations matrices, ANOVAs, and multivariate statistics. Two controlled laboratory experiments were conducted for this research. These experiments involved couples in relationships. Couples were brought into the lab and argued with each other across one of three technological media: face-to-face, telephone, and instant messaging (IM). In one set of couples' experiments, the couples argued for twenty minutes; in the subsequent couples' experiment, couples were encouraged to take as much time as they needed for their arguments. One of the main results from the first experiment is that couples did, indeed, argue when brought into a laboratory setting. One of the important findings for the second experiment is that time did not affect couples' tendency to reach closure during their arguments. This research is a contribution in that it examines how people engage in highly emotional communication using various technological media. In a society with ever-increasing communication needs that require technology, it becomes necessary to study its communicative affordances. Understanding the context of highly emotional interactions between members of couples gives insight into how technology meets (or fails to meet) these communication needs. / Ph. D.