Ko Yao Noi remains a beautiful island, where most people still believe that the island should be preserved from human degradation. It is often described as one of the last islands in the region to not be overly developed.
Ko Yao Yai is also a natural beauty, remaining the least developed of the two islands. Ko Yao Yai is significantly larger than Ko Yao Noi due to a lack of (basic) infrastructure in some areas of the island.
Sea Gypsies (Moken people) were inhabiting the Bay before anybody else, except maybe other nomadic people like forest hunters and collectors (Sakai, Negritos). The 3,500 or so inhabitants of Koh Yao Noi are thought to be recent migrants from the Malay Peninsula (Satun, Trang).
The Mon population, linguistically and culturally belonging to the Khmer ethnolinguistic group, did settled in peninsular Thailand since ever, ruling maritime states like the one of Ligor (Nakhon Si Thammarat). They melt continuously with Southern migrants from Malaysia and with Northern rulers (Thai), over centuries of commercial exchanges and political conflicts. Most probably the Mon stock remains prevalent for most of the people living nowadays in Southern Thailand, including people of Koh Yao.
Numerous cave paintings hidden in the many islands of the bay, extending from 2000 years ago to last century, attest the influence of distinct communities in the emergence of a mixed origin population, living now in the provinces of Phang Nga, Phuket, Krabi and Satun.
The most recent migrations (17th-18th century) from Satun and Trang to Ko Yao Yai and Koh Yao Noi is attested by the fact that the particular dialect spoken on the island still bear obvious Malaysian lexical traces, particularly regarding toponyms and vernacular names of the flora species.
The main industries on the island are fishing and rubber planting. A little rice farming and some fruit, palm and coconut plantations are evident. Boat building and farming techniques here have been passed from father to son and, while some of the youngsters leave Ko Yao to seek the bright lights of Phuket, most return to their tight knit community.