根據許多理論，隨著現代社會的變遷，由族群所構成交友的封閉性或階層界限將會減弱；然而事實上，在許多社會裏，族群間教育、職業分布不同的隔離增加，族群交友界限也增強。而台灣可說很特別，族群間教育、職業與居住隔離減弱；不過三十年來台灣地區的族群交友界限確實有明顯減弱嗎？這是族群間居住、教育與職業隔離減弱的鉅視結構變遷，增加族群接觸機會所造成的嗎？這些問題雖具有重要社會學意義，相關研究卻非常有限，仍有待於進一步的嚴格量化研究來探討。本研究則運用兩份分別於1970年與1997年進行調查的全國性樣本資料，採用對數線性與相乘分析，探討上述問題。研究發現顯示：族群交友界限有明顯減弱，這可歸因於族群間居住、教育與職業隔離的效應減弱；不過比起外省與閩南的交友，客家與外省、閩南交友相對機會一直偏低，這可歸因於客家居住地一直集中於桃竹苗地區，而與外省、閩南有較大的隔離。這些發現都可用Peter M. Blau所強調的「鉅視結構因素」 做解釋。

Results from studies on inter-ethnic relations indicate increases in educational and occupational segregation among ethnic groups and decreases in friendship choices across ethnic lines. Data also show that educational, occupational, and residential segregation in Taiwan has decreased dramatically among sub-ethnic groups based on provincial affiliations. We examined changes in friendship boundaries across ethnic lines using log linear and multiplicative analyses of island-wide surveys conducted in 1970 and 1997. Our findings show that choice of friends across sub-ethnic groups has actually increased substantially, with changing boundaries of ethnic friendships resulting from decreases in residential, educational, and occupational segregation. However, the data indicate that members of the Hakka ethnic group are less inclined to make friends with members of other sub-ethnic groups, perhaps due to their restricted distribution to a few Taiwanese counties. We use Blau's macro-structural factors to explain our findings.