Intermarriage with other tribes is very rare, despite the carefree attitudes many Yao circles have concerning courtship and marriage. It is quite common to see members of Lahu lives who have sought refuge in Yao villages, living with the Yao and working for them. The Yao keep a cautious but active trade relationship with Yunnanese, who travel in and out of their villages, but very rarely allow them to settle with them (as the Lisu quite often do ).