Sibling rivalry

Sibling rivalry is a near universal human phenomenon (Fig. 1). Sigmund Freud viewed the sibling relationship primarily in terms of rivalry for parental love. In 1899, Freud, reflecting on the fierceness of children’s dreams, wrote: ‘Hostile feelings towards brothers and sisters must be far more frequent in childhood than the unseeing eye of the adult observer can perceive’. The term ‘sibling rivalry’ was only introduced in the 1930s, by the US child psychiatrist David Levy. Levy practised play therapy in which children were given celluloid dolls, which they were told represented their younger sibling and breastfeeding mother, and encouraged to act out their feelings from when their mother breastfed their sibling. The usual result was a fierce and often homicidal attack on the dolls. Levy reproduced this response using play therapy with Guatemalan Indians, and so did colleagues working with native Argentinians. Levy said, ‘The aggressive response to the new baby is so typical that it is safe to say it is a common feature of human life’. The extent of sibling rivalry is complex and appears to vary with birth order, parental responses and external factors. A strong marital relationship has been shown to predict older siblings’ ability to regulate sibling jealousy. Sibling rivalry can vary in intensity from annoyance to murderous rage. Siblicide occurs in some birds, notably boobies, eagles and cattle egrets, and some animals like spotted hyenas, although wolf and lion cubs in contrast tend to protect siblings – not attack them. Sibling rivalry occurs early and often in the Bible and the Qur’an. Cain (Qabeel), the firstborn son of Adam and Eve, murdered his brother Abel (Habeel) after God preferred the younger brother’s offering (Fig. 2). Sisters Leah (Lia) and Rachel (Rahil) were rivals for the love of Jacob (Yacoub), who himself had tricked his elder brother Esau (al-Eis) out of his inheritance. The older brothers of Joseph (Yusuf ), son of Jacob (Yacoub), plotted his death and sold him into slavery. Some parents are reluctant to acknowledge sibling rivalry. The mother of boys aged 2 and 4 years in a research study gave birth to a girl. When I asked about sibling jealousy, she denied any. ‘Even at feed times?’ I asked. She admitted that the boys did come and cuddle up to her when she was breastfeeding. The baby would soon start to cry, and the mother said she had