Shirtsleeves to shirtsleeves in three research generations. A project on the science of science and the exceedingly rare circumstances that sustain research legacies from a mentor to mentee and to theirs: A case study on firearm research.

Background: In the 50 years since public health firearm research began, the decades have witnessed several pioneering investigators, followed by NRA backlash and a CDC funding moratorium, then increasing firearm mortality punctuated by mass shootings, and finally an unprecedented release of funding dedicated for research and to support trainees. Motivated by my own efforts to stay productive in firearm research, by the shirtsleeves-to-shirtsleeves cautionary lesson that wealth - for us this a researcher's funding, infrastructure, and capacity - amassed by one generation will soon diminish, and by my worry that we are not adequately dedicated to growing new investigators, I set out to document researcher lineages in this field.

Methods: I created a multigenerational lineage map to find authors using "gun" or "firearm" in the title/abstract as a way to find peer-reviewed publications on firearms as a public health issue. I designated the first author as Gen1 if the manuscript was sole authored or the senior author had never been first author on a firearm publication. I plotted each Gen1 author at the year of their first first-authored publication, and pointed from them to subsequent "first-time first-author investigators" (Gen2) for whom they were senior author, and so on for a Gen2 serving as senior author for a Gen3, and so on in that lineage.

Results: Gen1 authors numbered 91 by 2023, the first being Rushforth in 1974. Rushforth, 14 years later, produced the first and his only Gen2 author, Paulson, who produced no Gen3 authors. The field had produced 6 Gen2 authors when the first Gen3 author appeared in 1993, who produced the first Gen4 author in 1998, 14 years after Kraus that initiated that lineage in 1984. To date, only 5 lineages have produced a Gen4 author and among those only one lineage, from Schwab in 2002, has produced a Gen5. Twenty-four Gen3 authors have emerged. Only 35% of Gen2 authors produced a Gen3.

Conclusion: I hope this motivates years-long strategies to help trainees become established, informed by modeling quantitative and qualitative data to identify characteristics underlying the investigator network related to productivity and shortcomings alike. Without dedication to understand the science of science, shirtsleeves-to-shirtsleeves in three generations may be the fate of firearm research.