Abstract
Software development is highly dependent on human efforts and collaborations, which are immensely affected by emotions. This paper presents a quantitative empirical study of the emotional variations in different types of development activities (e.g., bug-fixing tasks) and development periods (i.e., days and times), in addition to in-depth investigation of emotions' impacts on software artifacts (i.e., commit messages) and exploration of scopes for exploiting emotional variations in software engineering activities. We study emotions in more than 490 thousand commit comments across 50 open-source projects. The findings add to our understanding of the role of emotions in software development, and expose scopes for exploitation of emotional awareness in improved task assignments and collaborations.