With a falling birth rate, most people have fewer brothers, sisters and cousins and it's also becoming increasingly rare for them to live just around corner. So friends and colleagues of all shapes and sizes often fill gaps and take on roles that extended families commonly filled just a generation or two ago. Other new sources of help in times of crisis include self-help groups and TV advice programmes. More..

At best, sibling rivalry can mature into friendly competition; at worst it can degenerate into arguments, estrangement and unhappiness all round. Sibling rivalry is an ancient tradition. The oldest book in Western civilisation, the Bible, tells the tale of Cain who murdered his irritating younger brother, Abel. More..