From the outside the Maasai appear to have a very homogenous culture, but important differences exist in dialects and cultures among the various Maa speakers, to the extent that a strict distinction between Maasai and non-Maasai is difficult to make.
Also, Maasai society is more open to other cultures than one might think. Trade and other forms of inter- action with others is an indistinguishable aspect of their culture. For example, specialists from hunter tribes called dorobo are hired to conduct the circumcision act, since the Maasai believe the job of cutting human flesh is pollutive labour ('dorobo' means 'poor' - by inference, those without cattle).
Indeed, it may well be because of the unique combination of a strong cultural identity, sense of superiority and an open (pragmatic) attitude to interaction with others that Maasai culture is still very much alive today. And this despite many predictions to the contrary (already in 1901, a book was published bearing the title 'The Last of the Maasai'). That said, there are certain key elements which both Maasai and non-Maasai label as typical for the 'real' Maasai culture, notably their highly specialised pastoralism and sophisticated age-set system. These are both enabled by some other, recognisable cornerstones of Maasai culture: respect, discipline and a sense of sharing.