It must be borne in mind that the Mafulu people have been very little in touch with white people, the missionaries, who have only been there since 1905, and on rare occasions a Government official or scientific traveller, being almost the only white men whom the bulk of them have ever seen; and they have been but slightly affected by the outside influences which for some years past have been constantly brought to bear upon the natives of the adjoining coast line and the people of the Mekeo plains; so that comparisons of these people with their more up-to-date [ 25 ] neighbours as regards their relative natural characters may well be in some respects misleading. Subject, however, to this caution I would say that they are lazy and easy-going (though not so much so as the Roro and Mekeo people), lively, excitable, cheerful, merry, fairly intelligent (this being judged rather from the young people), very superstitious, brave, with much power of enduring pain, cruel, not more revengeful perhaps than is usual among uncivilised natives, friendly one with another, not quarrelsome, but untrustworthy and not over-faithful even in their dealings with one another, though honest as regards boundaries and property rights and in the sense of not stealing from one another within their own communities (this being regarded as a most shameful offence), and of very loose sexual morality.
— from The Mafulu: Mountain People of British New Guinea by Robert Wood Williamson