Participants were told the experiment would take place in an adjacent building, though it really took place on the short walk there.

That's when the Manchester United fans encountered an injured man on the sidewalk.

As they walked by, one by one, researchers saw to it that one third of the time the injured man was wearing a blank t-shirt. One third of the time he was wearing the t-shirt of the arch-rival Liverpool team. And one-third of the time the injured man wore a Manchester United t-shirt.

Researchers then tallied the responses of their participants, 32% stopped to help the injured man wearing the plain t-shirt, 30% stopped to help the injured man wearing the Liverpool soccer t-shirt, while the injured man wearing the Manchester United t-shirt received assistance a whopping 92% of the time.

The idea that you and I favor those like us is a deeply ingrained evolutionary trait designed to keep us safe from predators and enemies.

Its conscious and unconscious manifestations influence where we live, work, and socialize. And properly dealing with it is at the heart of where our gospel will take us this holiday weekend as we commemorate, as a nation, that great unifying celebration called Independence Day.

This is when citizens in the most diverse nation in the world come together around our Nation's flag, celebrating a system of government aimed at giving us life, liberty, and the pursuit of happiness. And we do so with a lingering conviction that patriotism, unchecked by a higher loyalty, often goes off the rails.

Overcoming our preference for those who are like us makes a nation work, and makes us work to our highest potential. This is what Jesus was trying to get at when we will hear his epic words on Sunday, explaining that we are to love those who are not like us, friends and enemies, "for if you (only) love those who love you, what reward do you have?"

And this is the key to handling the darker sides of our diversity and the deep challenges of our divisions.

Our higher loyalty must be love.

We must consider the dignity and worth of every human being.

We must take time to get to know those who are not like us.

We cannot write people off because they're wearing the wrong t-shirt.

So this weekend, let us be quick to care, slow to judge, and ambitious about getting to know people who are not like ourselves. In this, let us be known: by our love.