Competing Explanations Can All Be Right (and Still Incomplete)

Psychology has a long habit of treating theoretical disagreement as a problem to be solved rather than as a condition to be understood. Competing explanations are framed as rivals in a contest for correctness, with empirical testing positioned as the mechanism by which one will eventually prevail. This posture reflects an assumption borrowed from domains where phenomena are comparatively stable and unitary. In psychology, it routinely misfires. Many competing explanations are not mutually exclusive, even when they appear to contradict one another. They are often addressing different levels, aspects, or functions of the same phenomenon. Their incompleteness lies not in their falsity, but in their scope.

Explanations in psychology operate at multiple levels simultaneously. Biological accounts emphasize neural, genetic, or physiological mechanisms. Cognitive accounts focus on representation, appraisal, and information processing. Social and cultural accounts attend to norms, roles, and relational structures. Developmental accounts trace trajectories over time. Each of these explanations can be empirically supported, internally coherent, and practically useful, while still failing to exhaust the phenomenon under study.

The problem arises when explanatory levels are conflated or allowed to compete as if they were offering the same kind of answer. A neural explanation does not invalidate a cognitive one. A cognitive explanation does not negate a social one. They answer different questions, even when they concern the same behavior. Treating them as competitors produces unnecessary conflict and encourages theoretical imperialism, where one level attempts to absorb all others.

This pattern is visible across the history of the field. Consider debates over emotion. Physiological theories emphasize bodily response and neural circuitry. Appraisal theories emphasize cognitive evaluation. Social constructionist accounts emphasize language and cultural meaning. Each has generated robust empirical findings. Attempts to declare one approach correct and the others mistaken have repeatedly stalled. The persistence of the debate reflects not confusion, but the multidimensional nature of emotion itself.

Donald Hebb’s distinction between levels of analysis remains instructive here. Hebb cautioned against expecting explanations at one level to replace those at another. Neural mechanisms constrain psychological function, but they do not render psychological description redundant. Similarly, psychological explanations do not dissolve social or cultural structure. Explanatory sufficiency depends on the question being asked.

The tendency to collapse levels is reinforced by methodological preference. Explanations that align with dominant methods acquire disproportionate authority. When neuroscience ascended, neural explanations were treated as deeper and therefore more real. When cognitive models dominated, computational explanations were treated as foundational. This hierarchy reflects institutional prestige more than epistemic necessity.

By the time I was trained, this hierarchy was already shaping how students were taught to think. The implicit message was that progress involved moving downward, toward mechanism. Higher-level explanations were tolerated as provisional or heuristic. What this obscured was that mechanisms alone do not explain meaning, intention, or normativity. They describe enabling conditions, not lived organization.

The incompleteness of explanations also becomes apparent in applied contexts. Consider depression. Biological models emphasize neurotransmitter function and genetic vulnerability. Cognitive models emphasize maladaptive beliefs and information processing biases. Interpersonal models emphasize relational loss and role transitions. Each framework supports effective interventions. No single framework fully accounts for the disorder’s heterogeneity, course, or lived experience. Treating one as definitive impoverishes both theory and practice.

Paul Meehl warned that psychology’s tolerance for “theoretical promiscuity” could lead to conceptual chaos. But his concern was not with pluralism itself. It was with the absence of constraints. Multiple explanations can coexist productively when their domains, assumptions, and limits are specified. Chaos emerges when explanations are allowed to overlap without articulation, or when they are treated as interchangeable.

The field’s discomfort with incompleteness often drives premature synthesis. Integrative models promise to unify disparate explanations into a single framework. While integration can be valuable, it frequently proceeds by flattening differences rather than preserving them. The result is a model that gestures toward multiple levels without doing justice to any. Integration becomes rhetorical rather than analytic.

A more disciplined pluralism would treat explanations as complementary rather than competitive. Each explanation would be evaluated for what it clarifies and what it leaves untouched. Tensions between explanations would be treated as informative, signaling where phenomena resist simplification. In this view, theoretical disagreement is not a failure to converge, but an index of complexity.

This stance requires a shift in how evidence is interpreted. Evidence supporting one explanation does not automatically disconfirm another operating at a different level. Yet psychological discourse often treats it as such. A neural correlate is reported as if it replaces psychological explanation. A cognitive mechanism is treated as if it supersedes social context. This zero-sum framing distorts inference.

Case-based reasoning again exposes the limits of singular explanation. Individual cases often demand multiple explanatory frames to be understood adequately. Biological vulnerability may interact with cognitive patterns and social stressors in ways that cannot be reduced to a single cause. Treating these interactions as confounds rather than as constitutive features of the phenomenon reflects a preference for simplicity over accuracy.

Accepting that competing explanations can all be right, and still incomplete, requires tolerating uncertainty. It resists the desire for theoretical closure. It also demands intellectual humility. No single framework can claim sovereignty over psychological life. Each offers a partial view shaped by its assumptions and aims.

Psychology’s task is not to eliminate theoretical diversity, but to manage it intelligently. This involves clarifying levels of explanation, articulating boundary conditions, and resisting the temptation to treat empirical success as ontological victory. Progress consists less in replacing old explanations than in learning how they fit together, and where they do not.

The discipline’s maturity will be measured not by how quickly it resolves disagreement, but by how well it understands why disagreement persists. In a field studying complex, meaning-laden organisms, incompleteness is not a flaw to be eradicated. It is a reality to be worked with.

Letter to the Reader

If theoretical disagreement has ever felt like a sign that psychology lacks coherence, reconsider that reaction. Over time, what becomes clear is that many disagreements arise because different questions are being answered at once.

Learning to ask what kind of explanation a theory offers, and what it leaves aside, is a crucial skill. Competing explanations are often invitations to think more carefully, not to choose sides prematurely.

Psychology advances when it learns how to hold multiple truths without forcing them into false unity.