As the first born, am I the smartest? Maybe – but siblings shape us in far more interesting ways | Imogen West-Knights

A new book about sibling relationships, The Family Dynamic by Susan Dominus , examines how things like birth order and achievements of your siblings affect a person's life trajectory.

Siblings shape you in ways that are less deliberate than parents.

Eldest children apparently outstrip their younger counterparts in cognitive tests by as early as their first birthday.

And for all that we bicker, it’s a beautiful thing to be loved by people who, unlike your parents, are not hard-wired to love you unconditionally, but who know you just as well as your parents do, and for almost as long. - Imogen West-Knights is a writer and journalist.