Most technologies don’t overhaul human motivations. Instead, they act as enablers for preexisting biological or cultural tendencies — new outlets for old habits. Once a technology becomes pervasive enough, it may significantly influence cultural trends, but many of the principles underlying behavior before and after the technology remain substantially the same. People do what they do regardless of the avenue.

The Internet is a prime example of an enabler for social behaviors on an unprecedented scope. Winston Shi points out that “while the way we live our lives has changed, friendship is fundamentally the same.” Social media doesn’t instill a desire for connection; it just facilitates ways of building it. Forums, blogs and essentially any sites that allow people to comment on them can help like-minded people find each other. The resulting communities create a real sense of comfort and belonging for the people that find them and often provide a valuable platform for marginalized groups. The flipside, though, is that it can become dangerously easy to fall into homogenous, polarized camps — to segregate ourselves along ideological lines. The consequences for us — and for our societies — are profound.

In his book “The Righteous Mind,” moral psychologist Jonathan Haidt remarks on the inherent “groupishness” of humans. We like to be a part of something bigger than ourselves. It causes us to gravitate toward mosh pits or orchestras, helps us organize our loyalties and our social circles. Because of it, we work toward the good of people other than ourselves.

But belonging to a group comes at the cost of dividing everyone into two categories: “us” and “them.” Perhaps counterintuitively, it’s easier to do that in a bigger community, just as a matter of sample size. Researchers at the University of Michigan found that in smaller schools, people are more likely to have diverse friendships, simply because it’s harder to find other people who are like them. But the larger the school, the less diverse their personal relationships tend to be, since it’s easier and more comfortable to band with like-minded individuals.

We also tend to read opinions we already agree with — to, as Haidt puts it, look for reasons why we can believe things we intuitively like and reasons why we mustn’t believe things we intuitively dislike. Studies on Internet habits reflect this tendency: People on the web segregate by political opinion, preferentially reading blogs they agree with, which in turn preferentially link to other blogs of the same partisan alignment. Political retweets follow the same pattern (although, interestingly, mentions do not). And both liberals and conservatives have their own brand of dealing with opinions that differ from theirs: On Facebook, liberals are more likely to block or un-friend people for making political statements they disagree with, while conservatives are less likely to see these statements in the first place.

Thus, the sheer size of the Internet community serves as a double-edged sword, giving individuals an easy way to find others that will accept them but at the same time giving them the means to insulate themselves from differing views.

What do we do? Research by numerous universities and companies such as McKinsey indicate that the synthesis of disparate opinions leads to higher-quality, more creative work and better financial performance at the office. But unease with differences — and the lack of obvious commonalities around which to congregate — can erode loyalties in large, diverse communities like cities, where people are less likely to volunteer, give to charity and trust their neighbors, according to research by Harvard political scientist Robert Putnam. We are enriched by our interactions with people who aren’t like us, forming bonds over what makes us unique — yet we can feel like outcasts without people that share our beliefs and experiences. How do we encourage diversity without division? How do we encourage unity without erasure?

There may not be a good answer, and reasonable people will disagree. It is essential that we realize the implications of living in an era where technology gives more people across the globe more opportunities to interact with each other — or to ignore each other.

So what groups are you a part of? Why do you count yourself as a member of these groups? What makes them groups? Now ask yourself: Are there groups that overlap with these groups? That contain these groups? What makes them groups? What unites people in these groups?

Not everybody has to be your best friend. The vast majority of people won’t be. But everyone in any group has something in common. Think about what that is, about what that means beyond the instinctive ideological camps to which we adhere — sometimes blindly, sometimes consciously, sometimes instinctively, sometimes self-righteously.  Because until we stop believing “we” are right and “they” are wrong, we may never see the intersections of our communities for the opportunities they are.

Contact Mindy Perkins at mindylp ‘at’ stanford.edu.