Research published in the Journal of Neuroscience says that 8-9 year old children learn radically different from 11-13 year olds and adults. The difference relates to how children of different ages process negative and positive feedback.
According to researchers, 8-9 year old children respond
disproportionally inaccurately to negative feedback whereas the opposite
is true in 12 year olds. As negative feedback generally signals a need to adjust current behavior, the younger children have a more difficult time interpreting it. The ability to make the interpretive leap necessary to respond accurately to negative feedback appears to develop as children become closer to the age of 11.
This information can have significant consequences for volleyball coaches teaching children under twelve.
The research, Evaluating the Negative or Valuing the Positive? Neural Mechanisms Supporting Feedback-Based Learning Across Development is available at the Journal of Neuroscience website here.
 von Duijvenvoorde, A., Zanolie, K., Rombouts, S., Raijmakers, M., Crone, E. (2008). Evaluating the Negative or Valuing the Positive? Neural Mechanisms Supporting Feedback-Based Learning Across Development. The Journal of Neuroscience 28(38) : 9495-9503.