It is impossible to fear the unknown. As a psychologist (or at least a psychology student) I have read about many issues where this may be the cause of harsh judgments or bigotry.
What if there was a simple way to fix this problem? What if just by exposure to different lifestyles, we could marginally decrease prejudiced and discrimination? Wouldn't we want to try it?
The world is facing issues now that it has never had to face before. Theses problems are partially because the world is so damn big! Full of so many different culture, ideas, and personalities. There is no easy way to fully understand what a culture you have barely heard of is going through, but there is a close second.
People who study abroad voluntarily take themselves out of their own culture and become immersed in a completely different environment. They are no longer able to eat the same food. They must adapt to the new social norms. They get a first hand look at a different country. Students that study abroad have to modify their own lifestyle and live the way the country lives.
Not only that, but to fit in, students must observe and learn from simple social interactions. By being apart of a culture, students learn a different appreciation for a countries. More of an appreciation that could EVER be learned through sitting in a classroom listening to a professor.
Seeing as I have never studied, I cannot say for certain everyone will be a better person because they have traveled to a different country, but they will have had exposure to a different environment. There's this term is social psychology called the mere exposure effect that says just by being around a certain person or environment, people will gain a slight fondness for it because they become more familiarly with it.
Working study abroad into a student college curriculum could be the change society needs to inspire students to become more open-minded. College try to do this with general education courses, like woman and gender studies or art history, but just because they are in that course doesn't mean they will retain any information from it. Most students barely pass classes like that because they couldn't care less.
Study abroad forces students to listen and participate. An example could be instead of taking an art history class, send them to Rome. Go to museums and stare at the different statues of David. Place them in front of the Trevi Fountain, so they are able to appreciate its true beauty. Not to mention, depending on where a student wants to go, it could count as a foreign language credit.
This may not be the answer for everyone, but it wouldn't hurt. Forcing college students to step out their comfort zone is exactly what college is about. Study abroad is just another way to encourage students to grow.