Abstract
Parkour is an activity characterized by the athletic, acrobatic, and efficient interaction of the athlete with the urban environment. Through training, skilled Parkour athletes (Traceurs) overcome everyday obstacles that are typically thought of as insurmountable, including the most common element of the modern carpentered landscape - walls. According to theories of Action-Modulated Perception (AMP), increased ability to jump and climb walls should correspond with perceiving walls as shorter. Traceurs and novices (age, height and sex matched) performed visual matching tasks on three walls (194 cm, 229 cm, and 345 cm), and also reported their subjective ability to climb the wall. Results show that Traceurs see walls as significantly shorter than novices, but only on the higher two walls. This pattern corresponds to the subjective difficulty ratings given by all participants, as novices reported the higher two walls as being significantly harder to climb than the Traceurs. The role of ability for action in perception is considered.