To reach or not to reach? Perception of body effectivities by young infants

Two experiments compared 6-month-old infants as they reach for an object. A ll were proficient reachers but with different levels of sitting ability. T he object was presented at various distances, within and beyond reach of th e infant. In the first experiment, the scaling of perceived reachability in infants with different postural abilities (i.e. non-sitter, near-sitter, a nd sitter infants) was explored. The second experiment investigated the rol e of proprioception in the scaling of perceived reachability by non-sitter and sitter infants. In general, results suggest that perceived reachability is calibrated in relation to the degree of postural control achieved by th e infant. Infants demonstrate a sense of their own situation in the environ ment as well as a sense of their own body effectivities. Both determine the execution, or non-execution, of reaching for a distal object by young infa nts. Copyright (C) 1999 John Wiley & Sons, Ltd.