 Equal numbers of males and females will be recruited to participate. If the sample participating in either experiment fails to perform in the manner expected, additional participants will be recruited at older test ages to identify when in the course of development such behavioral guidance emerges. As successive test ages will be separated by 6 month intervals, independent samples of 18-, then 24-month-old children will be recruited until the expected pattern of adaptive actions is observed cf. Fossberg, et al., 1992. 