Textures and Flavour Models

We discuss the implications of the measurements of neutrino masses and mixing angles for an underlying theory of flavour. The near bi- tri- maximal mixing observed is significantly different from the small mixing angles observed in the quark sector. If this structure is due to an underlying family symmetry it suggests the symmetry be non-Abelian in nature in order to relate the different family Yukawa couplings responsible for generating the mixing angles. We discuss how the combination of a non-Abelian family symmetry together with the see-saw mechanism can explain why there are large mixing angles in the neutrino sector while the mixing angles in the quark sector are small. Phenomenological implications of such a family symmetry are discussed.