Although Elizabeth Edwards knew her husband John had been cavorting with his spunky campaign worker Rielle Hunter at least since he publicly confessed to it in 2008, the couple stuck together, weathering the mistress even as she appeared to be inching closer to the Edwards' family home in North Carolina.
The marriage finally fizzled this week, days after Mr. Edwards admitted to fathering baby Quinn with Ms. Hunter. The former senator squeaked his confession out days before the publication of a tell-all detailing their turbulent affair.
In a twist on the infidelity scenario, reports are emerging that Elin Nordegren may stand by Tiger Woods. While it was a text from the golfer to Rachel Uchitel - "You are the only one I've loved" - that had Ms. Nordegren reaching for the golf clubs, she's reportedly had a change a heart after spending five days at sex addiction rehab with her husband.
Both cases prop up long-standing, cross-cultural research into jealousy that suggests women view emotional infidelity as a much more serious breach of trust than sexual trysts. Research has also shown the reverse is true for men, who often get more jealous about a partner's sexual infidelity than emotional betrayal.
Now, a study from Pennsylvania State University, to be published next week in Psychological Science, is shedding new light on why genders are jealous about different scenarios, beyond the evolutionary hypothesis.
Researchers have long theorized that men are hyper-vigilant about sex because they need to be certain of their paternity, while women are more concerned about emotional duplicity because they need partners who are committed to raising a family and in it for the long haul.
In the current study, researchers asked 99 men and 317 women - undergrads aged 18 to 55 enrolled in first-year psychology courses at two New York colleges - which they would find more distressing: sexual or emotional infidelity? The respondents also filled out questionnaires about their attachment styles in romantic relationships.
Fifty-four per cent of men said they would feel more upset about a sexual betrayal, compared with 24 per cent of women. When it came to emotional infidelity, 76 per cent of women found the prospect more painful, compared with 47 per cent of men.
But when the researchers looked at the numbers within each gender, it was clear that men found emotional betrayal as heartbreaking as they did sexual infidelity.
The questionnaires revealed a correlation: Men and women who prized their autonomy over commitment in relationships were much more upset about sexual than emotional infidelity. Meanwhile, those who were emotionally attached were much more likely to get miffed about emotional betrayal.
"Attachment explained which group they fell into," said Kenneth Levy, an assistant psychology professor at the university who co-authored the study with psychological scientist Kristen Kelly.
As for why the detached lovers were so greatly affected by sexual infidelity, Prof. Levy said, "I think it's probably ego."
He added that sexual jealousy is routinely linked to stalking, domestic violence and homicide. He hopes the study will play into developmental education that focuses on how children attach to others at an early age.
"The standing evolutionary theory didn't provide much guidance in how to intervene. It essentially said, 'Men are being men - what are you going to do?' " Prof. Levy said.
"This perspective suggests that we need to figure out ways to increase attachment and security. We know a bit about that, at least at a developmental level."