"However, we found the robustness of the effects on passionate love surprising." In two studies with about 150 couples, the researchers used the "Fast Friends" activity, originally developed by Arthur Aron of Stony Brook University, a co-author on the new study.
Indeed, perception is vital in a relationship, according to a range of new studies.
According to new research, striking up a friendship with another couple in which you discuss personal details of your life will bring you closer to your own partner.
"So whatever the ultimate explanation, I do not think the phenomenon is real," Coan says.
"I think it has to do with the conceptualization of one's relationship." "It may not even be about marriage, per se, but about asserting cohabitation instead," he explains.
Such interactions, the researchers say, may cause us to perceive our partners and the relationship in a new light.
Indeed, perception is vital in a relationship, according to a range of new studies to be presented this week at the Society for Personality and Social Psychology (SPSP) annual conference in Austin.
Coan conducted a parallel study with 26 same-sex couples, none of whom were legally married but half of whom described their relationship as a marriage.
They found the same difference in hypothalamic regulation by hand-holding between self-described married and self-described cohabiting same-sex couples.
Threat cues signaled to subjects that they faced a 20 percent chance of electric shock to their ankle, while the safe cues signaled a 0 percent chance of shock.
Some of the time, subjects held the hand of their partner, while other times, they either held the hand of a stranger or faced the cues alone.
In one of the studies, couples who met each other through the high-disclosure Fast Friends activity reported higher feelings of passionate love than those assigned to a low-disclosure task, which involved non-emotional, small-talk questions.