Developmental continuity? Crawling, cruising, and walking

Abstract

This research examined developmental continuity between "cruising" (moving sideways holding onto furniture for support) and walking. Because cruising and walking involve locomotion in an upright posture, researchers have assumed that cruising is functionally related to walking. Study 1 showed that most infants crawl and cruise concurrently prior to walking, amassing several weeks of experience with both skills. Study 2 showed that cruising infants perceive affordances for locomotion over an adjustable gap in a handrail used for manual support, but despite weeks of cruising experience, cruisers are largely oblivious to the dangers of gaps in the floor beneath their feet. Study 3 replicated the floor-gap findings for infants taking their first independent walking steps, and showed that new walkers also misperceive affordances for locomoting between gaps in a handrail. The findings suggest that weeks of cruising do not teach infants a basic fact about walking: the necessity of a floor to support their body. Moreover, this research demonstrated that developmental milestones that are temporally contiguous and structurally similar might have important functional discontinuities. Keywords crawling; cruising; walking; locomotion; developmental continuity Developmental ContinuityThe question of developmental continuity-"Where do new skills come from?"-is a central and long-standing issue in developmental psychology. Proponents of developmental continuity claim that new skills grow from the seeds of prior accomplishments. One line of evidence that old and new skills are related is adjacent temporal ordering, where a new skill appears in the footsteps of its predecessor or as one skill disappears another quickly appears on the scene. A second line of evidence is physical similarity, where old and new skills are similar in form or map onto each other structurally. The most important line of evidence is shared psychological function, where the earlier and later appearing skills rely on the same underlying psychological mechanisms to accomplish the same goals. In this case, experience

An Embodied Approach to Perception

“…As was briefly discussed in the previous section, learning new affordances requires agency, experience, and time. Babies, for example, are not sensitive to the size of a gap that they can step over when they first learn to walk (Adolph et al, 2011).…”

“…As Adolph's research shows (cf. Adolph, Berger, & Leo, 2011), babies learn through experience those environmental affordances that are consistent with their current behavioral repertoire and continue to learn new affordances as their new action capabilities develop.…”

Visually guided navigation: Head-mounted eye-tracking of natural locomotion in children and adults

“…Modeled after the adult work where participants repeatedly encounter an obstacle in their path, numerous laboratory studies with infants and children have examined visually guided locomotion over and under barriers (Schmuckler, 1996; van der Meer, 1997), across gaps in the surface of support (Adolph, 2000; Adolph, Berger, & Leo, in press), and down cliffs, slopes, and stairs (Adolph, 1997; Cowie, Atkinson, & Braddick, 2010; Kretch, Karasik, & Adolph, 2009). Novice infant walkers fare poorly, frequently tripping over barriers and falling over the edge of a drop-off.…”

Fear of Heights in Infants?

“…For example, human infants (and altricial animals such as kittens) require several weeks of self-produced locomotor experience before they avoid the deep side of the visual cliff (Bertenthal, Campos, & Barrett, 1984; Held & Hein, 1963). Likewise, on a real cliff, a large gap in the surface of support, or an impossibly steep slope (Figures 1B–D), infants plunge right over the edge unless they have many weeks of locomotor experience (Adolph, 1997, 2000; Adolph, Berger, & Leo, 2011; Kretch & Adolph, 2013a). These apparatuses have no safety glass; experimenters catch infants if they begin to fall.…”