Children without a mother have a more difficult time in social situations. Research also suggests that children without mothers have lower intelligence levels and do more poorly in school than children with mothers.
Studies indicate that without the nurturing of a mother, children's brains do not reach their full size. The part of the brain most affected is that responsible for human memory. Children with poor memories tend to have trouble learning. These children also lose out on critical training that children receive from their mothers in how to process stress and emotion.
Children left abandoned in orphanages in eastern Europe for long periods of time have experienced difficulty adopting to family life and are sometimes emotionally flat. Scientists suspect that the lack of a nurturing mother is also linked to childhood depression. Children may also develop obsessive or odd behaviors in response to not having a mother and are less likely to be able to maintain focus. Research has repeatedly shown that whether or not children lived in a clean, well-run facility without a mother was not a factor in how the children responded. Their emotional development was determined almost exclusively by the amount of one-on-one attention they received.