There is a moment in climbing when the wall ceases to be an object. The holds, the rough textures, and the volumes stop being inert matter and begin to respond to the presence of the body. This change does not occur in the rock or in the mind, but in the invisible space where the two meet. That point of contact -that intermediate zone where body and environment mutually recognize each other- is where the concept of effectivity comes to life, one of the most original and least understood ideas in Michael Turvey’s ecological psychology.

Turvey expanded James Gibson’s theory of affordances- those opportunities for action that the environment offers to an organism- and proposed that such opportunities exist only insofar as the body possesses the dispositions required to actualize them. He called those dispositions effectivities. They are not skills in the traditional sense, nor techniques acquired through practice, but relational properties of the organism–environment system. A hold affords being grasped only if there is a hand capable of closing on it, exerting friction and producing force; a surface affords balance only if the body possesses the organization and sensitivity required to maintain it. An affordance without a corresponding effectivity is an empty possibility, and an effectivity without an affordance is a potential without a world.

From this perspective, climbing is not about applying strength or technique to passive matter, but about discovering the possible correspondences between body and wall. Every movement is an update of the link between what the environment offers and what the organism can do. The same move may be trivial for an experienced climber and impossible for a beginner -not because the wall has changed, but because their fields of correspondence differ. Ecological training does not merely seek to improve strength or technique; it reconfigures how the body perceives the world. Each practice expands the repertoire of available effectivities, and with them, the number of affordances the environment reveals. In other words, to train is to expand the ability to perceive possibilities.

The wall, then, is not an enemy to be conquered but a territory to be completed. Every contact with the rock is a conversation: the skin senses humidity, the muscles interpret tension, the gaze perceives continuity between supports. The relevant information does not pass through rational thought or mental representation, but through bodily sensitivity. In Turvey’s view, to perceive is to act, and to act is to perceive. Both functions form a single continuous process that occurs not “inside” the subject but within the complete organism–environment system. In that cycle of perception and action, the body adjusts its behavior through strong anticipation, a direct coordination with the conditions of the environment. When an experienced climber moves, he does not rationally predict the next gesture; he feels it emerge from the continuity of action. His body perceives the relevant variables, angle, friction, tension, and responds immediately, as if thought and movement were the same thing.

This form of knowledge cannot be learned from a manual or observed from outside; it must be embodied. Each failed attempt, each fall, each micro-adjustment creates new connections between what the body can do and what the environment offers. Effectivity is, in this sense, a history of encounters. It resides neither in the muscles nor in the mind, but in the accumulated relationship with the world. The hand that has touched a thousand surfaces knows something that no verbal description could transmit; the foot that has trusted the friction of a sloping slab holds a tacit knowledge that cannot be explained, only enacted. Polanyi called it tacit knowing, and Turvey reformulated it as a form of intelligence distributed between body and environment.

Climbing makes that knowledge visible. There is no gesture that does not depend on a fine reading of the environment, and that reading is not carried out with the eyes but with the entire body. The climber who trusts his feet does not merely see the holds, he inhabits them. He feels them as extensions of his own equilibrium. Over time, his perceptual world changes: where once he saw obstacles, he now perceives paths; where there was fear, there is precision. Training does not simply modify strength or technique, it reorganizes the perceptual field, allowing new affordances to emerge in experience.

But effectivities are not stable. They change with context, fatigue, emotion, or age. A hold that felt secure becomes treacherous when the forearm locks up; a solid friction move turns uncertain when fear narrows attention. The field of possibilities expands or contracts with every breath. Climbing is therefore a constant conversation with the world, a practice of adjustment and readaptation.

This dynamic relationship also changes with age. The effectivities of the young body, based on power and speed, give way to others more subtle: sensitivity, economy of gesture, anticipatory reading of the wall. To age does not mean to lose capacity, but to reorganize the relation with the environment. Affordances that once felt natural disappear, yet others arise imperceptible to those who rely only on strength. The experienced climber learns to move within a different field of correspondences: finer, more patient, where balance matters more than impulse and precision replaces force.

Each fall, in this context, is not a defeat but an ecological measurement. It marks the exact point where an affordance ceases to be accessible to the current effectivities. But that limit is not fixed. With practice, attention, and variability, the frontier shifts. What was impossible yesterday can become obvious tomorrow. To train, at its core, is to expand the territory of the possible. It is not about mastering the rock but about transforming how the body and the environment coordinate. Improvement occurs in the relation itself.

This way of understanding climbing has a particular beauty because it redefines the very notion of the body. It is no longer a machine obeying mental commands but an open system that adjusts to the world with sensitivity and creativity. The body perceives, reasons, and decides simultaneously, without dividing experience into hierarchical layers. In practice, this expresses itself as embodied intelligence: the fluency of gesture, the ability to listen to texture, the calm that sustains movement under uncertainty.

Effectivities, then, are not just another technical concept within movement science; they are a way of understanding life as relation. To live is to possess possible responses to the world; to perceive is to recognize those possibilities; to act is to actualize them. The climber does not dominate the rock, he interprets it. He does not conquer height, he completes it. Each ascent is a negotiation between matter and consciousness, between the gravity that pulls downward and the desire that drives upward.

Effectivities reveal that what is possible is not a property of the world but a relation with it. Every human action depends on that capacity for response arising between body and environment. In climbing, this means recognizing that progress is not measured by the difficulty overcome but by the quality of that relationship. The broader and more refined the repertoire of effectivities, the richer the experience and the more intelligently the body can adapt to the complexity of the world. To train is to refine sensitivity, to detect what the environment allows and act accordingly.

To understand climbing from this approach requires a change of paradigm: it is no longer about mastering the rock but about coordinating with it. The wall is not an obstacle but a system that reveals the current state of our capacities. Each attempt, each adjustment, each error redefines that correspondence. Turvey invites us to think of perception and action as a single process, a circuit of information and response in which body and environment complete each other. In that precise coincidence between what the world offers and what the body can answer, the true knowledge of movement appears. There, in that equilibrium between necessity and possibility, begins the intelligence of the body.

References

Chemero, A. (2009). Radical embodied cognitive science. MIT Press.

Gibson, J. J. (1979). The ecological approach to visual perception. Houghton Mifflin.

Turvey, M. T. (1992). Affordances and prospective control: An outline of the ontology. Ecological Psychology, 4(3), 173–187.

Turvey, M. T. (2018). Lectures on perception: An ecological perspective. Routledge.

Polanyi, M. (1966). The tacit dimension. University of Chicago Press.

Csikszentmihalyi, M. (1990). Flow: The psychology of optimal experience. Harper & Row.