The Gaddang once comprised a large group in the Cagayan Valley region and are mostly found in Central Isabela, Nueva Vizaya, Quirino, and Cagayan. Most of them can also speak Ilocano, the lingua franca of Northern Luzon; the Gaddang language is closely related to Agta, Atta, Ibanag, Isneg, Itawis, Malaweg, and Yogad. Moreover, they're known by other names such as the Gadan, Gaddanes, Iraya, and Irraya, meaning “upriver”. They can be found in the eastern parts of Ifugao, the mountain province in Southeast Kalinga, and in the foothills of Cordillera Central. During the Spanish occupation, the lowland Gaddangs intermingled with other valley occupants, such as the Ibanags and Ilocanos, while others still, fled to the Cordillera and Sierra Madre Mountains to escape Spanish persecution. The population of this indigenous tribe is declining as they intermarry with and become absorbed by the larger groups. Their name derives from a combination of ga “heat” and dang “burned”, hence, they have have a darker complexion compared to other peoples of the Cordilleras. Chrisitans stereotyped them as 'untamed' and dangerous; in reality, they're of a calmer disposition compared to neighboring tribes.
The highlanders have maintained their unique culture, including their traditional costumes lavishly adorned with beads and precious stones. For instance, their ceremonial dress and ornamentation are some of the most elaborate and decorative; clothing of Western cut and commercial fabric are obtained from the lowland market. They have a penchant for decorating their clothes with beads, shells, buttons, and coins – sometimes covering significant portions of the clothing with ornamentations. Everyday attire, on the other hand, is simple, as evidenced by the men who don G-strings either in the homes or fields but don a pair of pants over their loin cloths when going to town. For ceremonies, men slip into loincloths (dinega), a small beaded jacket (koton), and cape (tapit).
Their residences are elevated and supported with tall posts of wood or bamboo that include a removable ladder that can be drawn up day and/or night to avoid intruders or enemies.
National Commission For Culture And The Arts, http://www.ncca.gov.ph/