New Delhi, May 19 -- The body of Tom Ochieng Mima is dressed in formal funeral finery, casket shaded from the hot western Kenyan sun as family and friends of the late 64-year-old settle into plastic chairs beneath white tents just off the roadside.

Wails pierce the air in a mix of lyrical song and unrestrained cries; a group of mourners wave leafy branches and beat them against the ground in a rhythm. A performance like this would not seem out of place at many funerals around the world - at first glance.

But this group of men and women never knew Mima, nor are they friends of his bereaved loved ones. They are professional mourners who are hired to openly and loudly express grief in line with local Luo cultural norms.

The role is an unl...