Local voters remain as polarised as ever nearly two decades after the Good Friday Agreement, according to a survey.
Just 4% of Catholics would give their first vote to a unionist party, while only 2% of Protestants would give their main support to a nationalist candidate.
The survey by the Electoral Reform Society is further evidence of the deep divisions in society and comes less than a fortnight before we head to the polls.
The study drew on data from more than 4,000 people questioned after the last Assembly election.
It showed only a minority would give their first-preference vote to a party from the other community.
Of all the preferences expressed by Catholics, just 8% were for unionist parties.
The equivalent figure for Protestants was 6%.
The study comes just days after UUP leader Mike Nesbitt sparked a row by indicating he intended to give his second-preference vote to the SDLP.
It prompted the resignation of Carol Black, a UUP councillor who said "the whole ethos of the party has been destroyed".
Last night former Alliance MLA turned political commentator Seamus Close said the findings were deeply depressing.
"I think it demonstrates that in Northern Ireland we are still very, very tribal," he added.
"When you look at election results, what you see is battles within tribes. In the last election 78% of the vote was divided between those two tribes.
"It epitomises all that is wrong with our society.
"It got me thinking back to the early days of the Alliance Party, which was the party that was founded to bring together the respective tribes. That was its whole raison d'etre.
"We were so convinced that this new concept of bringing people together within one political party would be the answer to Northern Ireland's problems.
"We were so convinced about that, and talking about it with nearly evangelical zeal back in the Seventies, that (we thought) everyone would hear it and respond. At the start it looked likely. Alliance was achieving around 14% in the local government elections in the Seventies, but now it is 6% or 7%.
"That things have slid backwards is, for the likes of myself, very depressing and annoying."
The report, titled The 2016 Northern Ireland Assembly Election: How Voters Used STV, took data from a poll of 4,043 people - both voters and non-voters - and was conducted immediately after last May's election.
The survey found:
Nearly 2,500 of the 4,043 people who took part filled out mock ballot papers reflecting how they voted, allowing a rigorous look at how they expressed their preferences under the single transferable vote system.
Analysis focused on the different communities, including the extent to which unionists and nationalists vote for other blocs.
The research was conducted by Prof John Coakley and Prof John Garry of Queen's University Belfast, Dr Neil Matthews at the University of Bristol, and Prof James Tilley at the University of Oxford.
Katie Ghose, chief executive of the Electoral Reform Society, said: "This report offers food for thought ahead of next month's Assembly election.
"What this research shows is that the single transferable vote system opens the door for a more open and less divided politics.
"And while voters aren't necessarily using it to the fullest extent yet, there's still a window of opportunity for it to grow when it comes to breaking down community barriers."