clipped from: www.we-make-money-not-art.com Among the Amazonian Desana, all members of a tribal group a believed to share a similar odour. Marriage is only allowed between persons of different odours, so spouses must be chosen from other tribal groups. This belief is expressed in rituals involving the exchanges of goods with different odours: one group will present the other with a gift of meat, for example, and receive fish in return. Some rituals involve the exchange of differently scented ants. The same goes with Batek Negrito of the Malay Peninsula who take the taboo a step further: not only is sexual intercourse between those of similar odour prohibited, but even sitting too close to one another for too long is believed to cause disease in the people involved and in any children they may conceive (via).
Research has demonstrated that humans use body odour to identify genetically appropriate mates.