The many instances of Indian influence do not justify the supposition that the Tinguian were ever directly in contact with that people.  The Malay islands to the south were pretty thoroughly under Hindu domination by the second century of the Christian era, and it is probable that they were influenced through trade at a considerably earlier date.  Judging from our data, it would seem that the Ilocano-Tinguian group had left its southern home at a time after this influence was beginning to make itself felt, but before it was of a sufficiently intimate nature to stamp itself indelibly on the lore, the ceremonial and economic life of this people, as it did in Java and some parts of Sumatra.  It is possible that these points of similarity may be due to trade, but if so, the contact was at a period antedating the fourteenth century, for in historic times the sea trade of the southern islands has been in the hands of the Mohammedanized Malay.  Their influence is very marked in the southern Philippines, but is not evident in northwestern Luzon.

Concerning the time of their arrival in Luzon, and the course pursued by them, we have no definite proof; but it is evident that the Tinguian did not begin to press inland until comparatively recent times.  Historical references and local traditions indicate that most of this movement has taken place since the arrival of the Spaniards, while the distribution of the great ceremonies gives a further suggestion that the dominant element in the Tinguian population has been settled in Abra for no great period.  The probable explanation for this distribution is that the interior valleys were sparsely settled with a population more akin to the Igorot than to the Tinguian, prior to the inland movement of the latter people; that the Tinguian were already possessed of the highly developed ceremonial life, before they entered Abra, and that this has been spread slowly, through intermarriage and migration, to the people on the outskirts of their territory.

These ceremonies are still practised by some families now residing in Christianized settlements in Abra and Ilocos Sur, while discreet questioning soon brings out the fact that they were formerly present in towns which have long been recognized as Ilocano.  The relationship of the Tinguian and Ilocano has already been shown by the physical data and historical references; but were these lacking, it requires but a little inquiry and the compilation of geneaological tables to show that many Ilocano families are related to the Tinguian.  It is a matter of common observation that the chief barrier between the two groups is religion, and, once let the pagan accept Christianity, he and his family are quickly absorbed by the Ilocano.

Uninterrupted trade with the coast in recent years, Spanish and American influence, have doubtless affected considerable changes in the Tinguian.  If, however, we subtract recent introductions, it is probable that we have in the life of this tribe an approximate picture of conditions among the more advanced of the northern Philippine groups prior to the entry of the European into their islands.