You Cannot Perceive a Relational Affordance (A Purple Peril)

One of the more enduring arguments in ecological psychology is about the best way to formally describe affordances. The two basic approaches are that they are dispositions (Turvey, Scarantino, me) or that they are relations (Reitveld, Kiverstein, Chemero). The argument has mostly settled down into just agreeing to disagree, but I am still convinced that the relational analysis is critically flawed and I want to try and either get them to solve the problem or end the debate once and for all. I've reviewed this in a bunch of places (e.g. here, here, and here)  but this post is just setting out my challenge once and for all; you cannot perceive a relational affordance, and there is as yet no good story about how to learn new affordances.

My problem stems from this Gibson (1979) quote (we all have our favourite, but this one seems to cut to the heart of it)

The central question for the theory of affordances is not whether they exist and are real but whether information is available in ambient light for perceiving them.

Right now, the affordances-are-relations camp have no story for how these can structure light (or other energy media) and therefore create information about themselves. They are therefore, as currently formulated, not even in principle perceptible. This means affordances-as-relations is of zero use to the ecological approach. 

Bruinberg et al (2018) tried to address this problem, but as I blogged here their solution is not ecological information and it reveals that these authors do not as yet understand what information actually is. My challenge is therefore this: tell me a story in which affordances-as-relations are able to create ecological information in energy arrays, and might therefore be learned, and the debate will be back on. Until then, affordances-as-dispositions is the only account that formalises the right properties and the debate is over. 

Scarantino (2003) “Affordances Explained”

Turvey, Shaw, Reed and Mace (1981) laid out an ontology of affordances; a formal account of the kind of things they are. They described them as dispositions, properties of the world constituted by sets of anchoring properties that offered an action to an organism whose dispositions could complement the affordance. Making affordances dispositions makes them real, makes them pre-date the interaction with the organism, and accounts for their odd ‘not doing anything until interacted with’ kind of existence. I am firmly Team Affordances are Dispositions and I have yet to meet an alternative account that supports a science of affordances or even allows them to be perceived.

The literature on dispositions was somewhat limited in 1981, but in 1998 Stephan Mumford published the definitive work on what they are and how they work. I always hoped someone with the necessary philosophy chops would use this work to strengthen the foundations of affordances (I even almost talked a philosopher into doing it!) but it turns out I’m covered. Andrea Scarantino (2003) published ‘Affordances Explained’ and did much of the necessary work, and there are some very useful things in the analysis. This post is me working through this material, translating from the technical philosophy into words I can understand better.