My dd was an extremely anxious child- shy, clingy. Frightened about things where all other children just kept playing. Here is an article I found about this and suggestion that they grow up with anxiety. My dd30 is off the radar with anxiety.
quote from article:
Could extreme shyness be traced to differences in the brain? Kagan, among others, predicted that behaviorally inhibited babies -- and the adults they would become -- might have an overly sensitive limbic system, and in particular an overly sensitive amygdala.[/i]
article:
www.sciencedaily.com/releases/2014/04/140417155901.htm