Toward the end of the first year, babies become more skilled at using their thumbs and forefingers to investigate objects. The ability to use a pincer grasp to pick up small objects and turn and twist items enables children to handle dials, knobs, and small moving objects like balls or bugs.
- Halverson, H. M. (1931). An experimental study of prehension in infants by means of systematic cinema records. Genetic Psychology Monographs, 10, 107