The T-Shaped Mathematical Scientist

Definition

When a discipline's growth is concentrated at its boundaries with other fields (see Disciplinary Boundary Erosion), the practitioners who create the most value are not those with the narrowest, deepest expertise alone, but those who combine that depth with enough breadth to work across the boundary. The report's Summary makes this explicit as a target profile, not an incidental nice-to-have: it recommends increasing the fraction of mathematical scientists who are knowledgeable beyond their own specialty, communicate well with researchers in other disciplines, understand the field's role in the wider world of science and business, and have hands-on experience with computation.

In the Book

The committee is careful to frame this as additive, not a replacement for deep specialists: "It is by no means necessary or even desirable for all mathematical scientists to exhibit these characteristics, but the community should work toward increasing the fraction that does." The report ties this profile directly to institutional design, not just individual aspiration — it calls for culture change, curriculum redesign, and reward-system adjustment (joint seminars, cross-listed courses, cross-disciplinary postdocs, courtesy appointments) so that people with this profile aren't penalized relative to single-discipline specialists under current promotion and funding criteria. It frames this as urgent because "the success and even the validity of many [interdisciplinary] projects depends on the early involvement of mathematical scientists" — meaning the translator role isn't a courtesy, it's often the difference between a project working and silently failing.

Why It Matters

This is a general answer to "should we train specialists or generalists" that avoids the false binary: the valuable profile is depth plus a translation layer, not breadth instead of depth. It also names a specific institutional trap — reward systems built for single-discipline specialists will systematically undervalue and underpromote the people doing the most structurally important work (bridging), unless the incentive structure is deliberately redesigned to recognize breadth as a skill in its own right rather than a diffusion of focus.