First, the husbands and wives rated the quality of their marriages on a scale of 0 to 151. Scores lower than 100 were considered distressed marriages.
Among couples chosen for the study, the husbands' average score was 126 and the wives' 127.
The researchers led by James Coan found that the wives in the best marriages appeared to have the calmest brains -- while holding their husbands' hands under threat.
Holding the stranger's hand was better than holding no hand at all but holding their husband's hand was best, the researchers found.