That Kennedy "credo" has also been seen in the third generation; Shriver's male cousins.
The late Michael Kennedy, son of assassinated presidential candidate Robert F. Kennedy, was married with three children when he was alleged to have had an affair with their 14-year-old babysitter. The girl refused to press charges. Kennedy was killed in a skiing accident in 1998.
William Smith, son of Jean Kennedy Smith, was charged in 1991 but later acquitted of rape while staying with his "Uncle Ted" at the family's Palm Beach, Fla., estate.
Shriver's own family life was not tarnished by rumored affairs. Mother Eunice, founder of the Special Olympics, and father Sargent Shriver, former vice presidential candidate, enjoyed a stable, 56-year marriage.
"Maria did admire her mother and father's relationship, but she had a different idea of what an ideal man was," Peele said. "She picked a bodybuilder, not an intellectual and empathetic kind of guy, saying, 'I want something more exciting.'"
At Sargent Shriver's funeral in January, about the time she learned of Schwarzenegger's love child, Maria Shriver eulogized her father -- in retrospect perhaps pointedly -- as a man whose greatest accomplishment beyond public service was, "how to treat a wife."
She said he taught his sons, "how to be a gentleman, a gentle man."
The Shriver-Schwarzenegger political alliance was an odd one: she a Democrat and he a Republican, but many were also baffled by other differences.
"I often wondered whether choosing a guy like him was kind of a rebellion," said Michael Diamond, a clinical psychologist from Los Angeles who specializes in trauma and relationship patterns.
"He didn't seem to espouse the family's liberal family values and didn't come from an intellectual tradition," said Diamond, who has not treated the couple. "There may have been some effort to break away."
Diamond said the intergenerational transmission of relationship dynamics are often at play in families like the Kennedys: "Presumably, when we talk about women who pick certain men, you would think they would know better.
"We see it all the time clinically -- most blatantly in trauma, like survivors of the Holocaust or other terrible tragedies of that nature," Diamond said. "We also see it in eating disorders -- often transmitted mother to daughter. We see abusive dynamics in a man and a woman repeating itself in the next generation.
"We also see it in narcissism when a father or mother creates a child who is equally narcissistic, although it may look different on the surface," he said.
Shriver is not to blame, Diamond said. The identification that takes place is often unconscious and unrecognized. And without therapy, the cycle continues.
In cases of infidelity, women often deny the truth, wanting to protect their children and to protect themselves. When Shriver denied allegations of Schwarzenegger's baiting and groping of other women, she suggested "the women were crazy," he said.
"It's very common," Diamond said. "To try to deny and rationalize it and see it as someone else's political agenda, to deny something that a deeper level you know is true. You have to go against yourself."
A long marriage, four children and plenty of "perks" being the wife of a celebrity governor can also make a wife deny the existence of infidelity, he said.
Positive Kennedy values -- an obligation to serve their country and to show compassion for the downtrodden -- were also in abundance. Those, too, transcended the generations and can be seen in Shriver's work with the Women's Conference and her commitment to raise awareness for Alzheimer's disease.
Her brother, Timothy, 52, is chairman and CEO of the Special Olympics, and brother Mark, 47, directs U.S. programs for the charity, Save the Children.
But Maria Shriver is still an "enigma," Peele said. "On the one hand, she fought for women's rights and asserted herself, and on the other hand, she may have enabled her husband's abuse."
The fourth generation of Kennedys, a large brood that includes the four Schwarzenegger children -- two boys and two girls, ages 13 to 21 -- might take several lessons from their father's indiscretions.
"They could learn one of two things or both," Peele said. "Noblesse oblige, as RFK cried for poor people, or the rules don't apply to us. We are the Kennedys."