Nuclear family is only acceptable family type because it has a
functional fit - performs functions that fulfils the needs of society.
All others are inadequate or even deviant.
Eg. Socialisation ensures that children can integrate
into society with norms and values, reducing social
problems.
A lone parent family cannot successfully socialise children
without male/female role model. They're less likely to spend
time with children as they are working, and children can turn to
deviant behaviour.
Criticism: Functionalists don't consider functional
alternatives such as education.