Northern Ireland would vote more strongly to remain in the EU if there was another Brexit poll, a study suggested.
A total of 69% would favour Remain if there was another referendum compared to 56% at the two years ago, the UK in a Changing Europe project said.
Catholics were much more likely to support a united Ireland if there was a "hard exit" in which the UK left the customs union and single market.
The Irish border is one of the most vexed questions facing negotiators who aim to strike a deal by the autumn ahead of the UK's withdrawal from the EU next year.
Brendan O'Leary, Lauder Professor of Political Science at the University of Pennsylvania, who also holds a visiting position at Queen's University Belfast (QUB), said: "Our results show that if there was another referendum, people in Northern Ireland would vote more strongly to remain in the EU.
"The proportion wanting to Remain has risen since the 2016 referendum as more people have become aware of the possible costs and inconveniences of leaving the EU, as citizens and as employees or employers."
The survey was carried out for the Economic and Social Research Council which is funding the UK in a Changing Europe project.
It said it provided an authoritative, non-partisan and impartial reference point for those looking for information, insights and analysis about UK-EU relations that stands aside from politics surrounding the debate.
Findings from the survey included:
- Catholics were much more likely to support a united Ireland if there was a hard exit in which the UK left the customs union and single market.
- 28% of Catholics would vote for a united Ireland if the UK changed its mind and remained in the EU while 53% of Catholics would vote for a united Ireland if there was a hard exit in which the UK left the customs union and single market.
- One in five Catholics found the possible use of cameras at the Irish border "almost impossible to accept" and nearly one in 10 Catholics (9%) would support cameras being vandalised.
- There were strong expectations that protests against checks at the Irish border or between Northern Ireland and the rest of the UK would quickly become violent.
- There was substantial support for a Brexit that would largely eliminate the need for any North-South or East-West border checks, namely for the UK as a whole to remain in the customs union and single market.
- 61% of the population favoured the UK as a whole remaining in the customs union and single market.
Principal investigator John Garry, Professor of Political Behaviour at QUB, said: "We find Catholics and Protestants most prefer the option that would avoid the need for any new barriers on borders.
"Either in the Irish Sea or across Ireland. They want the UK as a whole to stay in the customs union and single market."
He added: "However, what may surprise people is the extent to which Catholics oppose all borders within these islands."