Usually, someone responds to an opinion that differs from their own with, “Oh my god! I had no idea that you were one of those people!” That is another way of saying, “I thought that you were on my team!” In psychology, this is called false consensus bias. It's the belief that everyone is like we are and sometimes people get offended when someone who they value has a different opinion.
We are constantly exposed to millions of different opinions online, which can lead us (whether we mean to or not) to come to the conclusion that our friends are the normal ones and that there is some other group out there that is simply ridiculous. We subconsciously assume that this other group must be less intelligent than we are or less informed. This kind of behavior on social media is counterproductive and it's something that we, as a society, really need to move past.
When we find out that someone isn't "on our side," our first reaction is to run away or think that they're stupid. Now, I know that there are hateful, racist, homophobic, sexist, and xenophobic people out there. However, I’m talking about those people who believe in an opposing viewpoint of a complicated social issue for genuine, considered reasons.
This isn't about being politically correct, it's about not rejecting the possibility that the people who don’t feel the same way that you do might be right. We see this other group of people as a group of unintelligent, simple concepts, instead of the complicated human beings who they really are.
Sharing links or pictures that mock those with differing opinions doesn't mean that we're more informed. It means that we'd rather be smug assholes than consider an alternate viewpoint. It shows that we want our friends to think that we're like them, furthering the false consensus bias. We cannot say that we are "empathetic," only to turn around and belittle those who don’t agree with us.
We need to enter every issue with the possibility that we might be wrong this time. Isn’t it possible that we’re not right about everything? Could it be that people who live in different places than you do, who watch different TV shows, who listen to different music, and who read different books have opinions and belief systems that are just as valid as yours?
You won’t convince anyone to feel the way that you do if you don’t respect their position and opinions. The next time when you’re in a discussion with someone who you disagree with, don’t try to “win.” Don’t try to convince anyone of your viewpoint. Instead, try to “lose.” Hear them out. Ask them to convince you and mean it.
The next time when you feel compelled to share a link or photo, ask yourself why you are doing it. Is it because it confirms your worldview, reminding your circle of smart friends that you’re on their team or does that link brings to light information that you hadn’t considered?