Micki Sievwright has a new set of wheels that her husband constantly refers to as “my truck.” The same goes for their apartment and the backyard grill.

Turns out, the pronouns the Denver couple use count for more than mere semantics in the long haul. A new study suggests that “we” language used between spouses in times of conflict goes along with less negative behavior and signs of stress in lengthy marriages.

Previous studies have indicated that use of inclusive pronouns that include “we,” “our” and “us” – versus “I,” “me” and “you” – are evidence of marital satisfaction in younger couples like Sievwright and hubby Dane, both of whom are 27.

The latest work, in the September issue of the journal “Psychology and Aging,” carries the link forward to more established pairs when conflict bubbles, and it reports evidence of more relaxed heart rates and blood pressure among those with high “we-ness” quotients.

“We found more ‘we’ language in older couples and in happier couples,” said Robert Levenson, the study’s senior researcher at the University of California, Berkeley.

Levenson said “we” words over “I” words are “part of this invisible language that can tell scientists what’s going on inside a marriage.”

It’s a world so intimate and full of potential peril that honesty is sometimes sacrificed for saving face. Studying the tiny parts of speech is a valuable window because such words are often left uncensored in a marriage, though more research is necessary to determine whether marital bliss leads to “we” or the other way around, he said.

“It’s something that they’re not thinking about consciously and are probably not much aware of. It’s just a little chip of behavior that we can count,” Levenson said.

Each of 154 middle-aged and older couples in the study spent 15 minutes discussing a point of disagreement while hooked to heart rate and blood pressure monitors in Levenson’s laboratory. The researchers later watched videotapes of the interactions with attention to emotional behavior and the pronouns used, overlaid against the readings on physical stress.

The middle-aged couples were married at least 15 years, and those in the older group at least 35.

“When the ‘we’ language was predominant, those 15 minutes were emotionally positive and physiologically calm, and those were also the couples who were most satisfied with their marriages,” Levenson said. Marital satisfaction was based on written questionnaires the couples filled out.

The “me” pronouns were more closely associated than “we” language with negative facial expressions, tones of voice, body posture and gestures, the researchers said.

“It’s kind of like ‘there’s no ‘I’ in team.’ There were lots of hints about this,” Levenson said. “This might be one way to strengthen the partnership.”

The idea of giving up some “me” in favor of “we” in marriage has implications that reach miles beyond parts of speech and may also hinge on massive generational shifts, said psychology professor Doreen Arcus, who delves into family issues at the University of Massachusetts Lowell.

Arcus, 57, said personal pronouns in relation to identity were the least of her worries when she and Dan wed 28 years ago.

“We were fanatical about equality,” she said. She kept her name and insisted on shared wedding bands over an engagement ring, for instance.

There were other rules: They took turns sleeping on the side of the bed closer to the windows and the breeze, cooking dinner, sitting at the side of the table with the better view, balancing the checkbook.

“The list was quite extensive. Twenty-eight years later, we have settled into our own grooves, and together they work for us. I never did care if the checkbook balanced to the penny. I’m a better cook than he is,” Arcus said.

A practical test of the power of pronouns, she said, would be to instruct people “feeling deeper conflict to use more ‘we,’ and if you change the way they speak, does it alleviate the conflict? Language that does not reflect behavioral realities won’t fool anyone for long.”

For the Sievwrights, the transition from “me” to “we” is a work in progress as they look ahead to having kids and growing old together. Micki Sievwright wants her husband to stop calling the truck or apartment “his.”

“It’s likely a guy’s thing, but I’m trying to have him see these items as shared property, because I use them and own them just as much as he does,” said Sievwright, who married her college sweetheart a year and a half ago.

Dane is still struggling.

“I still have a tough time saying ‘we’ versus ‘me’ in many realms of our relationship. It was ‘me’ for 26 years of my life,” he said. “I wouldn’t have even noticed unless she told me the way I described these things bothered her.

“I think as time passes and with her reminding me enough, I’ll eventually say ‘ours’ as opposed to ‘mine’ when it comes to the things we have or the time we share.”

The Berkeley researchers focused on first-time marriages like those of the Arcuses and Sievwrights, but some who have been down the aisle more than once have learned a thing or two of their own about the power of pronouns.

Janet Wood, 51, of San Jose, Calif., was married eight years the first time and 10 years the second, and she has been in a committed relationship for six years.

“I remember in the last marriage, the heady days early on in our relationship when we were all romantic, and everything was ‘we did this’ and ‘we did that,’ ” she said. “Then one day, it changed to what are ‘your’ plans for the day, the weekend. That’s the time to start paying attention. I make a conscious effort to pay attention to this now, and my relationship is happier for it. It’s a small thing, but I believe it’s important.”