When I was a grad student (in America) a couple of decades ago, I was involved in two seminars/roundtable discussions that stayed with me. One was on sexual harassment- I'll save that for another thread. The other was a cultural awareness 'sharing.' For context, this was around the time of the Anita Hill testimony regarding Clarence Thomas
http://en.wikipedia.org/wiki/Anita_Hill
and the Tianaman Square protest
http://en.wikipedia.org/wiki/Tiananmen_Square_protests_of_19...
So sexual harassment and multicultural diversity were on the country's mind.
The department had a cultural awareness discussion centered on an exchange between the American graduate students and the recently arrived Chinese graduate students.
To my astonishment, the Chinese saw us American students as unfriendly, always retreating and 'sticking to our own kind.' They found it very hard to connect with us, much as they wanted to. It was because of the way we worked. When American students got their homework or assignment, we went to our desk and worked on it. We did the readings alone, we turned in the problems that we worked alone, and had very little discussion about the matter. We approached the courses individually, and this put the Chinese students off.
It put them off because they were very much about community. They discussed the lectures and reading until every single one of them understood it. They lived and died together. If homework was supposed to be individual work, then they did it individually- but they collaborated heavily on everything up until the point of homework- and they made sure everybody knew the concepts, math, etc. for doing the homework.
This is a very efficient way of learning new material. In fact, I've read in TIMS studies (or, books about the studies like 'The Teaching Gap' and 'The Learning Gap') that this is the asian way of teaching and learning in lower grades as well. There was less of an emphasis on (or, perhaps better, less of a recognition of) individual talent as being the basis of success in school, and more of a culture of "we can all get this together, if you can't it's because you are unwilling to work."
So I am not at all surprised that you observed heavy collaboration- I would be disappointed, however, if you saw deliberate 'cheating.' I can sympathise that people who don't fathom the concept of individuality in learning may struggle to understand the line between what we accept as cheating and not cheating. But that is not to say that they don't, and cheat anyway.