In once sense I'm completely sick of this subject and hate to see completely unrelated subjects slide to this discussion in forum threads over and over.
In another it keeps coming up, so it seems as well to address it directly. I just did discuss it a little with one of the few expats I talk to here by message, and just saw a Quora question on the same exact point, so I'll share what I wrote there.
In a sense it's almost the wrong question, because it implies that completely integrating is ideal, and striking a balance between embracing some aspects of local culture and not personally taking up others is sub-optimum or maybe even unworkable. So I mentioned that, that the implication is problematic, but I did go on to pass on my take on the literal question. It's almost too long to cite it all here but it seems rude to not, to excerpt a paragraph or two and then expect others to go elsewhere to read further. Skipping reading any of it might be the best option; who cares what I think? Here it goes anyway.
https://www.quora.com/Can-foreigners-in … n-Bickel-5
This question is almost too familiar, since discussions related to it just won't stop in expat groups, and lots of other topics end up sliding there. The short version: some can and some can't. Speaking or even reading and writing Thai are one critical sticking point. That really maps onto a broader divide relating to foreigners either integrating quite a bit or trying to retain a foreign cultural perspective and strike a balance related to changing over only what they want to adjust.
I'll get the language issue out of the way first. Some foreigners adapt to life in Thailand fairly well with limited local language use. Integrating is another matter. If the idea is to become as Thai as possible obviously speaking fluent Thai is closely related to that. My Thai isn't very good, limited in vocabulary range and not properly pronounced. But I do work in a Thai company, only associate with Thais, for the most part, eat Thai foods, have been a Thai monk, travel more in Thailand than in other countries, have two Thai and US citizen kids, and so on. The balance works but I'm not as integrated as I could be if I spoke fluent Thai.
Back to that divide related to integration. It comes up in discussion because expats crowd into two camps, one very well integrated, and very positive about Thailand, and the other not very well integrated, in lots of cases expressing lots of criticism of Thai practices and culture. The strange part is that there are pros and cons related to any country or culture (or individual life, when you get to it), so it becomes hard to separate out the bias in what others choose to communicate from the interpretive bias in what they actually experience. Almost no one ever says that there is good and bad in the differences between Thailand and their home country, and that their own lives go well in some ways and not as well in others. My sense is that what people want to project and what they actually interpret mix. They're not just either optimists or pessimists, and not just out to spin themselves as having a great life or resentful and open to projecting bitterness, but those two factors combine.
I was a natural fit in Thai culture for some reasons related to who and how I am. I'm relatively quiet and prone to getting along well with others, not as loud, confrontational, or opinionated as lots of people can be. That split isn't intended as positive and negative as it might come across. My wife, who is Thai, is a bit high strung, more vocal, and prone to not emphasizing getting along with others as much as trying to get them to do what she wants them to do. In short, we both match the other's culture better (in that sense, at least). My older brother is a lot like that in a lot of ways, with a very direct and assertive personality, which matched well with going into the military. Neither approach is necessarily good or bad. Either might work best when somewhat moderate, not so assertive that someone can't get along well with others, and not so agreeable to prevent pushing through to an immediate goal if resistance comes up.
I'm not saying that this is the key to getting along in Thai culture, to integrating. My wife is well integrated here; she's Thai, born and raised in Bangkok, only ever spending three years living abroad in the US when we met in grad school in Hawaii. Personalities vary everywhere. To fit in here though someone has to strike a balance with how Thais see and do things. My wife's approach works because she's familiar with when to let that go, and when she can go with her natural inclinations. She has also been raised with the myriad of minor do's and don'ts of Thai culture, so beyond that one broad theme she knows what to do and not do in any given circumstance. Bargaining comes up a lot in tourist questions, and works as an example: she knows when that's appropriate and when it's not. It's not stressful to her in the least as a factor.
Language is one main key as much as anything else, and broad trends in personality type may or may not match with Thai culture well, and the little details add up, but someone really needs to be open to changing how they look at things to integrate. That is just a sum of those things, in a sense, but it almost goes beyond all that. It's not just doing something appropriate in one situation and knowing not to say something in another, it's a shift in perspective. Of course I started with claiming someone could go to an extreme with integrating to enjoy life as a foreigner here, or strike any number of different balances related to that.
It wouldn't be necessary to become a Buddhist, for example, but it wouldn't hurt, and depending on what someone means by “fully integrating” it may need to include that to count. Of course I think a devout Christian could integrate well here, or an atheist. I had studied Buddhism for over 15 years prior to coming here, and had just left off completing two degree programs related to that, a second bachelors and a masters in the study of religion and philosophy. I'm still not exactly Buddhist in the main Thai sense but for the most part I do accept the teachings as one of the main influences in my life. It helps related to understanding Thai perspective, and also to accepting being a family member. As an example my son just ordained for two weeks as a Thai Buddhist novice, and if I were a devout Christian I suppose that could've been a sticking point. Or even if I were a committed atheist, and against teaching my kids any religion. I'll mention a post about how that went for him: Keoni's take on being a Thai Buddhist novice monk
It took me about three years to really adjust to a Thai perspective, exposed only to Thais and their way of thinking and interacting, beyond internet access and television. I would think without some of those natural inclinations to fitting in that would've been more difficult. If I learned more of the Thai language it would go easier, even now, ten years in. I'm not great with languages, but I have studied and learned a bit of French, Spanish, and Sanskrit in the past. I get a sense that people who are naturally adept at languages have an easier time fitting in, and beyond that and almost separate from it people who want to be seen as well-integrated and have better language skills self-promote by playing that up. One expat friend here speaks only slightly better Thai than I do, still quite limited, and he's lived and worked here for half of his life, retired here now. Thai language skills help a lot but there doesn't seem to be any one key to integrating, even though if there is a main factor that's probably it. Liking Thai food doesn't hurt too, and hot weather, or dealing well with leaving behind everything in that other country.
There's one more set of issues that almost never comes up. Some expats are antisocial, or had whatever types of problems in their own lives in that initial home country. If someone wanted to be seen as an outsider, and naturally experienced that where they are from for other reasons (like just being an introvert), that might make for an odd form of natural fit living abroad. The most natural knee-jerk negative read might be that “losers” could do well in Thailand because they get a status boost due to just being “white,” and experience a natural sort of reset / do-over. I'm not trying to say that, but different levels of factors do come into play. For as difficult as it can be to shift perspective and deal with the range of foreign context issues I'd expect that these types of background condition might more typically lead to living abroad not working out.