President Donald Trump has spoken of the risk of radicals slipping into the United States from Syria as refugees, and most Europeans surveyed also believe that people from the Middle East seeking asylum raise the danger of terrorism in their countries.

Whether such concerns are well founded is the subject of a new survey conducted by psychology Professor Arie Kruglanski, along with colleagues David Webber, an assistant professor at Virginia Commonwealth University, Erica Molinario, a University of Maryland postdoctoral research associate, and Katarzyna Jaśko, a researcher in the Institute of Psychology, Centre for Social Cognitive Studies Kraków.

There appears to be little cause to fear, they write in a new essay in The Conversation.

While today’s news is full of stories about refugees and migrants to the U.S. from Central America, the plight of those particular refugees is only part of an international migration crisis that has been going on since 2015 and has driven 25.9 million refugees worldwide from their homes.

We study the psychological aspects of migration and have carried out a systematic study funded by the National Science Foundation of refugees from the Syrian civil war. Thirteen million refugees have fled the conflict that has ravaged Syria for the last eight years.

Some in the West have expressed concerns that Syrian religious extremists may migrate to the West under cover of the refugee crisis to do harm. That attitude was reflected by then-presidential candidate Donald Trump in a tweet from Nov. 17, 2015.

“Refugees from Syria are now pouring into our great country,” Trump tweeted. “Who knows who they are – some could be ISIS. Is our president insane?”

Trump’s fear of Syrian refugees has been echoed in Europe. A Pew Research Center study in 2016 found that 59% of European respondents believed that the coming of refugees would increase the likelihood of terrorism in their country.

So Syrian refugees are now marooned in refugee camps or other temporary venues, unable to migrate because of immigration policies borne, in part, of these fears.

Read the rest in The Conversation.