In the extended family, adult sons live with their fathers, were they have higher ascribed status. However, at work, the son may have a higher achieved status than his father- this would then give rise to tensions and conflict if they lived together. The solution is for sons to leave home when they marry, and form their own nuclear family. This results in a mobile nuclear family which is 'structurally isolated' from its extended kin- meaning it has no binding obligations to them, allowing the success of the talented.