I talk to strangers. I know, you're not supposed to — didn't McGruff the Crime Dog drill that into everyone's head in grade school?

But maybe it's just where I was raised — a little town in South Dakota that no one besides my closest friends has ever heard of.

At home it's the norm to greet everyone you meet with a friendly hello — whether you know them or not. When I get in the car to drive back to Notre Dame, I have to break myself of the habit of waving to every car that passes by.

One of my friends who is more familiar with "city life" has attempted to educate me about the error of my ways.

"The first rule is to never make eye contact. Everyone knows that," he tells me. "Erin, you're asking to be mugged."

It's possible that my life has been too sheltered. The Notre Dame campus isn't exactly crime central (Security evidently spends most of its time dealing with bike thefts and sports injuries).

But despite that, I refuse to believe his "rule."

I can't help it — I don't want to live in a world where a friendly smile can cause harm.

In my psychology class today, our professor told us about a woman who was murdered in her New York City apartment. Thirty-eight of her neighbors heard her scream for more than half an hour, but not one of them called the police or attempted to help. Are people really so uncaring that they wouldn't help someone they don't know personally — even when that person is in dire distress?

I'd really like to think not.

My family went on a vacation in Denver when I was seven. I've forgotten every silly tourist attraction that we visited, but one incident stands out in my mind.

It was the end of a long day and we were on a busy Denver freeway that runs through a poor section of the city. We were slightly concerned when our car began to make a funny rattling noise. Although my mom glibly pretended nothing was wrong, my sister and I exchanged worried glances.

Five minutes later, our car could go no farther. In the days before everyone had a cellular phone, we were in trouble. As cars frantically rushed by, we scanned the area in every direction, looking for somewhere to go for help. Nothing. Finally my dad decided he had no choice but to walk towards an exit several miles back.

Surprisingly, however, at that moment another car pulled off the freeway behind us. A man got out and asked, "Can we give you a hand?"

Soon we were at his home. While the man took my dad to get parts to fix the car, his wife and their children treated us as old friends who had arrived for a long-anticipated visit.

I'm forever grateful they had the courage to reach out to a carload of strangers.

And I hope fear won't keep me from doing the same.

• Watch out for strangers?