A landmark study by O'Neill (1996), in which 2-year-old children were found to be more likely to point toward a hidden object to help an adult who was unsighted during the hiding event than to point helpfully for an adult who had been sighted, seems to undermine the conventional assumption that children this young do not understand the…

A study investigated children's difficulty in learning color words and attempted to determine whether the difficulty was perceptual, conceptual, or linguistic. The subjects were 24 two-year-olds, half with knowledge of color words and half without, and a similar control group. The experimental subjects were given conceptual and comprehension tasks…