The power of well-connected arguments: early sensitivity to the connective because.

Connectives, such as because, are routinely used by parents when addressing their children, yet we do not know to what extent children are sensitive to their use. Given children's early developing abilities to evaluate testimony and produce arguments containing connectives, it was hypothesized that young children would show an appropriate reaction to the presence of connectives. Three experiments were conducted to test this hypothesis. In each, two informants gave contradicting statements regarding the location of an object and justified their positions by using a similar argument. Only one of the informants used the connective because to link his argument to the statement. In each experiment, the 3-year-olds performed at chance in selecting choices containing the connective because, but the 4- and 5-year-olds performed above chance. Moreover, in Experiments 2 and 3, the 4-year-olds, 5-year-olds, and adults performed significantly better than the 3-year-olds. These findings show that 4-year-olds, 5-year-olds, and adults are sensitive to the presence of connectives. An interpretation of the difference in performance between the 3-year-olds and the 4- and 5-year-olds in terms of metarepresentational skills is suggested.