Multidisciplinary vs cross-disciplinary

Are you aware of the difference between multidisciplinary and cross-disciplinary research? It’s like the difference between a multicultural and an intercultural environment. In a multicultural setting, different cultures coexist with limited interaction, while an intercultural environment is a melting pot where new cultures emerge, enriched by various contributions. Similarly, multidisciplinary research addresses different aspects of a problem through the expertise of various disciplines, with each specialist solving their part independently. In contrast, cross-disciplinary research explores uncharted territories at the boundaries of established scientific fields, where the most important scientific challenges and progress occur1,2,3. This often leads to the creation of new fields, such as Bioinformatics, Environmental Sciences, Cognitive Neuroscience, City Science, or Computational Social Sciences.

Many of today’s most pressing issues, such as climate change4, cancer research5, public health crises6, or sustainable development in education7, are complex and multifaceted, requiring holistic approaches. For instance, tackling climate change requires knowledge and contributions from climatology, economics, sociology, and engineering. However, this knowledge cannot be simply summed up to solve a complex, interconnected and dynamic system. Instead, addressing such problems requires understanding and integrating these complexities.

De-siloing strategy and the IFISC case

The need for a common fundamental expertise

The creation of the Institute for Cross-Disciplinary Physics and Complex Systems (Palma de Mallorca, Spain) dates back to 2007. The vision was to engage in cross-disciplinary research focusing on emerging strategic fields. At that time, while there were some pioneering initiatives and growing recognition of the value of integrating knowledge across different fields under the prism of complex systems (e.g. early example of Santa Fe Institute, 1984), most of the research was still conducted within traditional disciplinary boundaries8. Although there are some differences compared to 20 years ago, this has largely remained the same. Most multidisciplinary institutes host researchers with diverse academic and professional backgrounds to ensure a balanced representation of different disciplines. While this approach has proven effective, it is still limited by the retention of silos. Thus, the challenge lies not just in the coexistence of these fields but in fostering meaningful communication and mutual comprehension, as each discipline often has its own terminology, methodologies, and frameworks for understanding the world.

An alternative approach requires a shift in perspective and the appreciation that the growing complexity of cross-disciplinary fields could be studied and understood by starting from fundamental scientific fields. Following these principles, IFISC created a solid base of researchers with background in Statistical and Nonlinear Physics, complemented by members coming from engineering, mathematics, and computer science. This predominantly physics-oriented expertise is effectively used in the research context of complex systems. Counterintuitively, this does not oppose cross-disciplinarity, as the latter does not imply multidisciplinarity. Instead, a consistent background provides the necessary common language, methods, and tools for effective collaboration and a sense of belonging to a common undertaking.

In this way different research problems can be tackled using established methodologies. However, having researchers with a shared physics-oriented background and willingness to expand boundaries is not enough for effective cross-disciplinary research that integrate knowledge and challenge established ideas. This still requires external collaborations. For example, combining expertise from mathematics, biology, and computational sciences has led to models that predict seagrass responses to stressors9 and to photonic hardware platforms that apply neuro-inspired concepts for computing10. Similarly, complex systems and artificial intelligence methodologies that analyse social media lexical data have been applied to studies of cultural differentiation11.

Such collaborations require significant effort in coordination, with the development of a shared language, and the breaking of disciplinary silos12,13. For example, physicists often seek universal mechanisms, and biologists focus on the diversity in living organisms. Even basic terms such as “model” can have different meanings across fields. Bridging these gaps to achieve a unified research agenda and shared goals demands creativity, negotiation, compromise, and open-mindedness. As mentioned earlier, having researchers with a shared background is not enough and an organization that supports the process, adopting an innovative approach is thus essential.

Decentralized institutional organization at the core of a different scientific network

The structure of an institute focused on cross-disciplinary research must be more fluid and integrative than traditional institutes. A pyramidal structure, common in most research institutions, is no longer suitable. Instead, we need a decentralized structure, where there are no fixed, separate research groups. Leadership should be collaborative, with decision-making processes that emphasize consensus and inclusivity. With this in mind, we can then outline the features of the IFISC structure.

The roles within the leadership include an executive team that oversees the overall vision and strategy, and committees that undertake administrative tasks. The aspect that really makes the difference, however, is the research environment itself which is a self-organized complex system composed of nodes (researchers) seeking coherence and integration from diversity, interaction, scientific dialog, transversal structures, and bridge building (Fig. 1). Implementing this system affects all aspects of research. It includes designing physical spaces that encourage interactions across projects and career levels, fostering new ideas and collaborations. It also involves education through the Summer Undergraduate Research Fellowships and a Master’s degree in Complex Systems, which prepare students to address complex scientific and societal challenges through cross-disciplinary research.

Fig. 1: Network of joint journal publications among tenured IFISC members between 2007-2024.
figure 1

Each member is a node with a fill colour that represents the number of published papers affiliated with IFISC. The weighted connections between nodes are the joint total number of published papers, indicated by the scaled width of the connection lines. The largest number of connections of a single node is 11. The mean number of collaborations per node is 5.8. New links are created each year (red lines for 2023–24) with the incorporation of new scientists or new collaborations between existing members.

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To complete the picture, we need to redesign research organization, shifting the focus from research groups to research content. IFISC’s research is structured around four overlapping research lines: one develops broadly applicable methodologies, tools, and concepts, while the other three apply these ideas to physical, biological, and social domains. This structure creates opportunities to contribute to future challenges in digitalization, information processing and artificial intelligence, social and economic structures, health, mobility, climate, and environment.

The IFISC case

These aspects have proven to be optimal to promote unhampered collaboration among all the nodes of this research network, from PhD students to senior professors.

Early career stage

The organization aims at stimulating intellectual exchange between master students and doctoral candidates and holds weekly informal gatherings that foster cross-pollination of ideas related to the distinct research lines. Doctoral students also give annual talks on their research fields as part of their assessment and present their latest research findings to IFISC members and external visitors during an annual open-door poster event.

Advanced career stage and tenured researchers

Senior IFISC researchers participate in multiple research lines, leveraging transversality, interdisciplinarity, and collaboration. Research teams self-assemble in response to scientific or funding opportunities, with the freedom to evolve in time to optimize resources and output. They follow an open-door office policy, balancing the need for uninterrupted work with the benefits of spontaneous exchanges. This policy facilitates easier communication, encourages informal interactions between junior and senior researchers, and promotes a culture of transparency.

This approach shapes the institute’s research identity: more than half of its works are published in multidisciplinary journals or fields other than physics (Fig. 2). With significant contributions from international collaborations, IFISC is recognized as a center of excellence by the Spanish government and as a globally respected institute producing high-impact research across disciplines.

Fig. 2: Categorization of IFISC-affiliated publications during 2018-2024.
figure 2

Categorization of the 380 indexed published papers affiliated with IFISC, in physics, multidisciplinary, and non-physics journals, during 2018-2024.

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Conclusions

In summary, cross-disciplinarity is a valuable approach to scientific research, enabling the transfer of ideas across fields and creating new solutions to complex problems critical to society. Promoting this approach is challenging, especially when scaling from a single research group to entire institutions or networks. IFISC exemplifies successful implementation of these concepts, and their long experience draws effective and trustworthy guidelines for the creation of new, more diverse, and even more complex collaborative networks. Beyond the institution level, flexible infrastructure is needed to support self-organization and adaptation. Encouraging such a collaborative environment and investing in digital infrastructure for open-knowledge sharing systems will allows cross-disciplinarity to thrive, leading to scientific breakthroughs that are difficult or impossible to achieve otherwise.

Does this mean that the traditional deepening of knowledge in specific fields is an obsolete way of seeking progress and innovation? Not at all. Specialization has been a cornerstone of scientific achievements over the last century. Specialists are well-versed in the latest methodologies, theories, and technologies, enabling them to push the boundaries of what is known. Cross-disciplinary research, on the other hand, acts like a non-specialist, seeking opportunities at the borders of different fields. These opportunities often arise from new perspectives and transform contributions of limited interest into evolving research topics. While new disciplines emerge from such efforts, the subsequent maturation of these new fields typically involves researchers specializing in them, eventually transitioning away from cross-disciplinary activity. Scientific progress isn’t about of choosing one approach over another. The research landscape is a complex jigsaw puzzle, with deep specialization and cross-disciplinary exploration complementing each other. The true challenge is to find the most effective way to integrate the two, so that both strengthen the whole.