A French study has found that eldest children are probably more selfish than their younger siblings. The birth of a brother or sister seems to alienate eldest kids and they become naturally wary of others, said researchers from the Montpelier University.
The Daily Mail reported that eldest children seem to be shocked by the new arrival as they will no longer be the center of attention for their parents.
"Shifting from only to firstborn status following the birth of a younger sibling seems to lead the eldest child to reduce his or her co-operative behaviour," the researchers said.
However sometimes eldest kids tended to be over-protected and are unable to cope with stress.