Research cited by Richard Bowlby Jr, in the U.K. in his article Early Stress in Daycare, indicates that since the child’s right hemisphere is growing faster than the left hemisphere until sometime between 30 and 36 months, children who are under that age suffer in childcare. They cannot understand their mother’s absence. The brain is not geared to understand that the comfort of the primary caregiver will return and that this absence is only temporary. IF and ONLY IF the child has a secondary attachment figure from the moment they arrive in daycare until the moment they leave, does this problem resolve. The secondary attachment figure can be a teacher or caregiver, but they should not be shifted to other care givers during the day.
Of course almost no childcare center provides for this kind of security.
Research shows that children who do not have this attachment-smart daycare will suffer learning and attention issues later in life. THIS is part of the ‘trauma’ that results in ADHD. Research Richard Bowlby to find out more.