This study explores the psychological development of children, and specifically tests at what point the children doubt information being presented to them.  It turns out that young children have a surprising ability to sort out statements driven by self-interest and bias.  As parents, this is important because we need to communicate effectively with our kids as appropriate to their development, which is difficult to gauge at times.

This Yale study included 20 children in kindergarten, second and fourth grades who were told stories with characters assessing outcomes based on varying levels of self-interest.  Overwhelmingly, the kids believed the true stories over lies, but an amazing developmental leap occurred between kindergarten and second grade----they started recognizing that the statements made due to self-interest might not be accurate.  This is a primary level of critical thinking, and it is important to recognize that our kids can sort information on this level so we maintain healthy communications.