Human language and cognition represent one of the great paradoxes of the human species. They enable us to create science, develop technology, and connect in complex social ways. Yet, this very capacity often turns against us, dividing humanity into factions vying for dominance and resources.
It is as though every human being is riding a metaphorical tiger, tasked with mastering it with equanimity. Cultural evolution has the potential to aid us in this task, bringing with it the wisdom and insights accrued over generations. Yet, at its worst, it entrenches divisions and power struggles, often exacerbated by a science that historically mirrors these dynamics.
From Francis Galton’s eugenics to modern Western-dominated evidence-based practices, the field of psychological science has leaned heavily on WEIRD (Western, Educated, Industrialized, Rich, Democratic) perspectives. This dominance obscures the diversity of human experience and limits the generalizability of our findings. The current structure of research too often favors top-down, normative approaches that categorize rather than empower and that impose rather than adapt.
The solution may lie in focusing on biopsychosocial processes—those elemental building blocks of human change—rather than rigid diagnostic categories of one particular person (or couple or family or organization or neighborhood) as a time before we draw generalizations. Acceptance and Commitment Therapy (ACT) and its underlying process-based framework offer a pathway to this broader, more inclusive science.
ACT was built with these sensibilities in mind. You can see it in its process focus, in the early emphasis on single-case, experimental designs, qualitative research, and some of the earliest idionomic studies ever done in clinical psychology. And you can see it in the spectacular spread of process-oriented ACT throughout lower- and middle-income countries. Nearly half of the randomized trials ever done (of the 1,225 now posted) were done there.
Recent research done inside fairly typical but well-done randomized trials underscores this potential. Below, I describe a recent stepped-care trial conducted in Italy with migrant populations, including asylum seekers and undocumented migrants, and a study just out that compared ACT with trauma-focused cognitive behavior therapy (TF-CBT) for female Afghan adolescents experiencing posttraumatic stress symptoms (PTSS). Both studies highlight the importance of culturally and contextually sensitive interventions in mental health care.
The Case for Idionomic Analysis
A process-focused and person-centered approach to psychological science better enables us to address the unique needs of diverse populations than “one-size” normative approaches. It shifts the focus from rigid intervention protocols to tailoring interventions with small kernels that are sensitive to processes of change, as they are modified by cultural, spiritual, and contextual factors. This is particularly critical in addressing the mental health needs of marginalized groups, such as migrants and war-affected populations, whose lived experiences and cultural frameworks often diverge from those studied in mainstream psychological research.
For example, the stepped-care trial conducted by Purgato et al. (2025) in Italy combined two World Health Organization-developed interventions to reduce anxiety and depression in migrants: an ACT intervention called Doing What Matters in Times of Stress (DWM) and Problem Management Plus (PM+). Delivered by trained lay facilitators, they were shown to be scalable, transdiagnostic, and sensitive to cultural nuances.
The results showed significant reductions in symptoms of anxiety, depression, and PTSD compared to care as usual, highlighting the value of culturally adapted, low-intensity interventions for vulnerable groups. ACT alone resulted in a third of the group no longer needing care due to improvement at Week 7. The remainder of the experimental group was improving but had not yet met the criteria, so the Problem Management kernel was added. At week 14, 45 percent of the participants had passed clinical cutoffs for mental distress, nearly twice the rate of the control condition.
The study by Ahmadi et al. (2024) compared ACT and TF-CBT for adolescent Afghan girls who had experienced trauma, such as being exposed to suicide bombings. In some ways, it’s an even more interesting study because trauma-focused CBT is among our best technologies for dealing with trauma. Both interventions effectively reduced PTSS, but ACT showed unique advantages in addressing intrusive symptoms.
The authors explain it this way: “Religious teachings in Afghan society emphasize concepts of acceptance and coping with difficulties. Therefore, the ACT approach may be more acceptable to the Afghan people. In ACT, signicant emphasis is placed on values, which align well with Afghan religious society and may have contributed to the positive response from adolescent girls in this study.” (p. 1457). Said simply, the processes of change targeted by ACT were better aligned with cultural values, enhancing engagement and improving outcomes.
Why ACT Fits Diverse Cultural and Spiritual Needs
ACT’s focus on processes such as psychological flexibility makes it inherently adaptable. Unlike interventions rooted in rigid diagnostic frameworks, ACT emphasizes open, engaged, and value-based action, allowing it to integrate seamlessly with diverse cultural and spiritual traditions. In Italy, this flexibility enabled the adaptation of DWM and PM+ to the unique challenges faced by migrants. In Afghanistan, ACT’s alignment with cultural norms of acceptance and its use of metaphors and experiential exercises made it particularly effective for adolescent girls recovering from trauma.
These examples highlight the potential a more process-based approach has to bridge the gap between evidence-based practice and the lived realities of people from different cultures. By focusing on processes of change rather than surface-level symptoms, ACT can address the universal challenges posed by human language and cognition while respecting the specific contexts in which they manifest.
Toward a More Inclusive Science
The path forward in behavioral science requires a commitment to epistemological hybridity—integrating insights from Western science with the wisdom of Indigenous and non-Western knowledge systems. Idionomic analysis, process-based therapy, and interventions like ACT offer a framework for achieving this integration. By focusing on the processes that underlie human suffering and resilience, we can develop interventions that are not only effective but also equitable and inclusive.