This study was designed to gather data on the developmental progression of children's inhibitive capabilities in a naturalistic setting and to determine the stability of observed capabilities within a developmental period. One hundred and twenty-two 2-, 3- and 4-year-old children were given an opportunity to select an attractive toy and play with it for a short period, then ordered by an adult to stop playing with the toy. Three classes of inhibitive behavior were recorded: initial inhibition, short-term continued inhibition, and long-term continued inhibition (remaining stopped for 30 to 60 seconds, respectively). A second session three weeks following the first (with a different adult) assessed the stability of observed inhibitive behaviors. The proportions of children showing initial inhibition rose significantly with age, ranging from 43% of 2-year-olds to 77% of 4-year-olds. The stability of initial inhibition across experimental sessions also rose with age. The proportions of children showing continued inhibition also rose with age, but for long-term continued inhibition the presence of a female adult significantly reduced the proportion of older children demonstrating it. The results are discussed in terms of different processes mediating initial inhibition and continued inhibition during a delay period. (Author/MS)