Trust ain’t what it used to be in America.

Back in 1972, when the folks conducting the General Social Survey first asked a sampling of Americans if they trusted their countrymen, about half said they did.

Last year, when the same research outfit asked the same set of questions, only a third of our fellow Americans said they trusted one another.

The GSS folks found that Americans – black and white, rich or poor – are more leery, suspicious and mistrustful of others than ever before.

As long as the General Social Survey itself can be trusted, it both confirms and contradicts what my eyes and ears have been telling me for years.

On one hand, the survey found that about two-thirds of Americans believe “you can’t be too careful” dealing with others. The Associated Press followed up this year with a poll on some specifics.

Americans say they don’t trust other drivers not to crash into them.

They say they don’t trust the retail clerks who swipe their credit cards.

They say they don’t trust the people they meet when they are traveling.

The GSS didn’t bother to ask if we trusted the government or Wall Street or the mainstream news media. The AP found that 81 percent of Americans seldom trust the government in Washington.

No one needs a survey to discover that most of us believe those big American institutions can’t be trusted.

It’s also understandable why so many Americans, especially the young, don’t trust our leaders and social institutions like marriage, the church and the family.

A lot of young people have fallen out of trust with President Obama lately, for good reason. Ditto for churches.

And after seeing so many marriages break up, why would a young person trust her own marriage to last? Better to not get married in the first place.

Despite the survey results, however, the real problem might be that too many Americans – especially young ones – are actually too trusting in some ways.

Too many people of all ages still blindly trust that what they see on TV and the Internet is true. But when it comes to social media, kids – and too many of their parents – are incredibly trusting and naive.

By the millions, they post their personal data and deepest thoughts on Facebook. They email each other. They sext love notes to each other. They send out compromising selfies on their smart phones.

These over-trusting souls tell the whole world where they live, what they own and when they’re going away on vacation – and then they’re shocked to come home to a robbed and ransacked house.

In the Smart Phone Age, when everyone with an iPhone thinks he’s a news reporter, trusting everyone in the room or on the street with your secret or your politically incorrect opinion is a dumb idea.

Ask Mitt Romney. Ask Prince Harry. Ask Alec Baldwin.

It’s pretty clear that technology and social media have outrun our ability to handle them. Until we get a grip on them, until we learn to use them maturely, we shouldn’t trust them so much.

So who do we trust? We trust the people and institutions who earn our trust. And if no one is earning it, we have to learn to trust ourselves. I hope we still know how to do that.

Copyright ©2013 Michael Reagan