In the 2016 US presidential elections, Hillary Clintons shocking loss to Republican candidate Donald Trump may have been becasue her party, Democrats, were too willing to welcome people with differing views into their party, a study has found.
The study, published in the journal Leadership, suggests that the Republicans viewed Trump as strongly representing what they stand for -- creating party unity and success in the election.
However, Democrats' greater inclusiveness and willingness to integrate members of other groups as part of their own meant that they identified more with non-Clinton supporters - weakening party cohesion and leading to election defeat, researchers said.
"Political group processes had a major influence on the election," said Julie Christian from the University of Birmingham in the UK.
"The Democrats' approach valued inclusion and welcoming divergent views, whereas the Republicans were much more tightly-knit," Christian said.
One of the keys to Trump's unexpected campaign success was that Republicans viewed him as truly representative of their group, researchers said.
"By contrast, the Democrats' greater inclusiveness meant that they struggled to view Hillary Clinton as representative of the group," said Christian.
The study shows that Republicans displayed solidarity only with their own group and held more negative attitudes towards those not supporting their group's values.
This greater solidarity was a factor that may have enabled them to act more as a single entity.
Inclusiveness meant that, rather than members drawing a sense of distinctiveness from their Democrat party affiliation, they gained esteem by integrating others into their party.
This emphasis on the collective approach worked against Clinton by hampering Democrat supporters' ability to perceive her as delivering on and embodying the group's values, said researchers, including those from Claremont McKenna College in the US.
This outcome occurred because the group became too flexible with the inclusion of the opposition, they said.
The absence of endorsement for the leader and the use of this integration strategy worked to undermine the chance of a Democrat win.
"When groups must share a common environment after an election, the Democrats' inclusive approach would probably help to pull competing parties together," said Christian.
"However, a more inclusive approach looking for co-operation before the competition is won results in too much integration and loss of momentum for the group," she said.
The researchers note that the strategy of the Republican group to win the election is not necessarily suited to holding leadership after the election.
Their view is that the strongest option for the Republicans, post-victory, would have been to embrace as many Democrat 'out-group' members as possible to grow their 'in-group'.