This article explores historical sociology as a complementary source of knowledge for scientific research, considering barriers and facilitators to this work through reflections on one project. This project began as a study of the emergence and reception of the infant disorganized attachment classification, introduced in the 1980s by Ainsworth’s student Mary Main, working with Judith Solomon. Elsewhere I have reported on the findings of collaborative work with attachment researchers, without giving full details of how this came about. Here, I will offer personal reflections arising from the process, and my work in what Hasok Chang has called history as “complementary science.”