The Kaulong people, one of the dozens of small populations living along the southern watershed of the Island of New Britain, just East of New Guinea, formerly practised the ritual strangling of widows. When a man died, his widow called upon her brothers to strangle her. She was not nurderously strangled against her will, nor was she pressured into this ritualized form of suicide by other members of her society. Instead, she had grown up observing it as the custom, followed the custom when she became widowed herself, strongly urged her brothers (or her son if she had no brothers) to fulfil their solemn obligation to strangle her despite their natural reluctance, and sat co-operatively while they did strangle her.
From The World Until Yesterday, Jared Diamond's latest. I'm interviewing him tomorrow so I won't be blogging until very late at least.
Anyway, should be an interesting chat.