Everyone knows that grandma's cookies taste better because they're made with love and that phone calls to the cable company are less frustrating when there's a human being on the other end of the phone. But are these things really true? A University of Maryland psychologist devised a study that put them to the test.

The result: Food tastes better, pain hurts less, and pleasure is more pleasant when they come with good intentions behind them. And it doesn't even matter if the intentions actually exist--it's the perception that they're there that's important.

The general message is that being suspicious leads to a very unhappy life. Trusting in people's good intentions makes for a happier one. This doesn't mean that you should give away the house.

Seeing the world and the people in it as benevolent adds to life; seeing them with a jaundiced eye can turn life into a bitter pill.

The study involved three tests of pleasure, pain and taste. In the first test, people sat in an easy chair with an electric massage pad that was either turned on by a real human being or a computer. The massages were identical, but people consistently got more pleasure from the massages where a human flipped the switch. The massages initiated by the computer just weren't viewed as as good.

The second test looked at candy. People were given packaged candy with a note attached — Valentine's Day. One note read: "I picked this just for you. Hope it makes you happy." A second note read: "Whatever. I don't care. I just picked it randomly." According to the study subjects, the candy that came with the valentine tasted better and sweeter than the candy that came with the sulky message.

A third test looked at pain and involved three groups who received electric shocks from a "partner." Group One, the accidental group, thought they were being shocked without their partner's awareness. Group Two thought that their partner was shocking them maliciously. And Group Three, the benevolent group, thought their partner was shocking them for their own good, in an effort to help them win money.

People in Group Three, the benevolent group, reported much less pain from the shocks than people in the other groups did. Just the thought that the shocks had good intentions behind them made them hurt less.

Three simple experiments that show how good intentions can add to life.

There are a host of messages in these findings. One suggests that medical personnel should brush up on their bedside manner; their poking, probing and injections will hurt a lot less. Another is that being good to your relationship partner isn't good enough — they have to know that you mean it and really want them to feel good.

The general message is that being suspicious leads to a very unhappy life. Trusting in people's good intentions makes for a happier one. This doesn't mean that you should give away the house. But constantly seeing hidden agendas will take its toll. You'll be much better off giving people the benefit of the doubt.

Cynics might consider this a triumph of style over substance. And maybe they're right. But being right rarely makes life sweeter. Good intentions will.

An article on the study was published in the journal, Social Psychological and Personality Science.