“Lumpers” and “splitters” were terms originally used to describe scientists who applied centripetal or centrifugal forces, respectively, to the evolving species taxonomy and other nosology debates in the 1800s. The first use of these 2 terms is attributed to Charles Darwin: “Those who make many species are the ‘splitters,’ and those who make few are the ‘lumpers.’”1(p463) Indeed, evidence from cognitive science suggests that we have individual differences in the way we view information2; some of us process information in a way that leads us to perceive the “whole,” or similarities, in our research, practice, and teaching, whereas others of us process information in a way that leads us to perceive the “parts,” or the distinctions that can inevitably be found. These opposing information-processing and general tendencies are playing out in our approach to entities as different as the medical care that we provide, the medical reimbursement system under which we practice, and the types of research designs, questions, and approaches that we use in our science. For example, the Affordable Care Act seeks to promote the “lumper-friendly” Primary Care Medical Home in which it is intended that 1 team of clinicians will deliver comprehensive care for multiple chronic diseases, conditions, and symptoms rather than split this care among a disparate group of specialists across different health systems. Yet, at the same time, we continue to see “splitting” tendencies in medical care, as subspecialties continue to flourish,3 and the frequency and proportion of medical care that arises from referrals continues to escalate.4 Whereas there may be a normal distribution of lumping to splitting tendencies in the general population, scientists tend as a group to be splitters (as a gross stereotype). The impact of this splitting tendency on the research questions that scientists find interesting and the research designs that they accept as rigorous and worthy of funding is interesting to contemplate. It is also interesting to contemplate how lumpers (think “generalists” here) might view the usefulness and importance of research findings created and funded by splitters. Depending on the manner in which you characteristically process information, you are going to either be enchanted with or have grave concerns about one of the randomized clinical trials reported in this issue of JAMA Internal Medicine.5
Davidson KW, Kronish IM, Shaffer JA. An Innovative or Disconcerting Approach to the Psychosocial Care of Your Patient With a Cardiac Condition: Are You a Lumper or a Splitter? JAMA Intern Med. 2014;174(6):936–937. doi:10.1001/jamainternmed.2014.86
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