Poster #162 - Children’s Use of Everyday Artifacts: Cognitive and Perceptual-Motor Requirements of Unzipping a Zipper

• In Event: 1-169 - Poster Session 04
  In Poster Session: PS 04 Section - Perceptual, Sensory, Motor

Integrative Statement

The everyday world is populated with artifacts that require specific motor actions for the object to be used as its designer intended. Think about the first hour of your day: You turn the doorknob on your bedroom door, untwist the lid of the toothpaste tube, button your shirt, zip your jeans, flip the lid of the coffee pot, pull open the Tupperware lid, and so on. These common “motor routines” are so deeply engrained in adults that we take them for granted. But we know nothing about how children learn to use everyday artifacts.
We encouraged 18- to 41-month-old children to unzip a small transparent pouch (5.5 cm x 12.5 cm) with a large, red tab to retrieve a toy inside. Although unzipping a pouch may seem simple, it is not. The first step is to realize that the zipper tab must be pulled along the teeth. Then come the biomechanics of implementation. To zip or unzip, both hands must begin near the zipper tab, with one hand stabilizing the pouch, and the other hand grasping the tab with a pincer grip. The gripping hand must pull the zipper by applying force opposite to the direction of force exerted by the stabilizing hand and parallel to the direction of the teeth (Figure 1). If the forces are not in direct opposition and parallel to the teeth, the zipper stays zipped. Detailed and systematic description of developmental trends in this task serves as a model system to reveal how children develop effective perceptual-motor strategies to address the common but non-obvious demands required to use everyday artifacts.
Preliminary results from 35 children show that younger children (18-23 months) inconsistently displayed the required pulling action and were never successful (Figure 2). Instead, they squeezed or pulled both sides of the pouch, wiggled the tab, or requested help from the experimenter. All 24- to 29-month-olds displayed the pulling action—although they often used palmar grips and pulled in all directions, rarely opposite to the stabilizing hand and parallel to the teeth. Forty percent of children were successful (lightest red bar in Figure 2), but only after many tries. Between 30 and 35 months, 80% of children were successful, but still required multiple attempts and adjustments before success and thus, displayed long latencies (M = 15.8 s) before unzipping successfully. Strategies in this age group varied by pull direction, type of grip, and the location of the stabilizing hand. Finally, by 36 months of age, 100% of children were successful and demonstrated finer, adult-like pincer grips from the first pull. They immediately pulled in the effective direction, exerting appropriate and opposing forces with both hands, and almost all succeeded well within 10 seconds (M = 8.2 s). Thus, with age, children hone in on more specific actions in increasingly “warmer” regions of the search space until successful implementation. These findings provide insights into the perceptual-motor strategies that contribute to children’s discovery and implementation of the “hidden affordances” inherent in the artifacts of daily living.

Authors

• Brianna Kaplan, New York University
  Presenting Author

• Jaya Rachwani, New York University
  Non-Presenting Author

• Danyang Han, New York University
  Non-Presenting Author

• Catherine S. Tamis-LeMonda, New York University
  Non-Presenting Author

• Karen E Adolph, New York University
  Non-Presenting Author