Doggone affordances: Canine perception of affordances

10 Abstract Performing any behavior requires perceiving 11 affordances—whether and how that behavior can be per12 formed. Perception of affordances exhibits action scaling— 13 choices about when to transition between two different modes 14 of behavior reflect the fit between action capabilities and en15 vironmental properties. The boundary between distances that 16 are perceived to be reachable with an arm-only reach and 17 those that are perceived to be reachable with an arm-plus18 torso reach occurs at farther distances for long-armed than 19 for short-armed people, but at the same ratio of object20 distance-to-arm length for both groups. To the extent that per21 ception of affordances is supported by detection of invariant 22 stimulation patterns, perception of a given affordance ought to 23 exhibit action scaling regardless of species. We investigated 24 the heights at which dogs chose to transition from reaching 25 with the head only to rearing (i.e., reaching with the head plus 26 torso). This transition occurred at a taller height for tall than 27 for short dogs, but at the same ratio of shoulder-height-to28 treat-height for both groups. The results demonstrate a simi29 larity in perception of affordances across species and suggest 30 that perception of affordances is supported by detection of 31 lawfully structured stimulation patterns that may be invariant 32 across species.