The public's angry response to the octuplets' mom and reports that public money will be needed to help care for her children says a lot about human nature. While humans are wired to help and rescue others, there's a limit.

People can't empathize with this California mother because they judge her actions to be intentional and unfair, say social scientists.

The result: Rather than an outpouring of gifts and warm wishes for eight bundles of joy, vilifying voices have filled the airwaves.

"If the woman had eight children naturally or had her first fertility treatment and accidentally wound up with eight kids, I think people would still be thinking 'miracle babies,' and they would continue to be embraced by the popular media," said Daniel Kruger, a social and evolutionary psychologist at the University of Michigan's School of Public Health.

Without empathy, or an understanding of 33-year-old Nadya Suleman's situation, humans are not likely to pitch in and help (at least not voluntarily). And so news that public assistance, which is already helping to support some of Suleman's other six kids, will be required for the octuplets has some California taxpayers and others outraged.

"While on some level people can empathize with her desire to have children — a desire which most people share, and perceive to be positive — they still see her as having intentionally violated rules of fairness," said Nicola Knight, an evolutionary anthropologist at the University of Oxford in England. "If this birth had been spontaneous, conversely, she would have been congratulated."

Moral judgments

We feel good when we help others, especially when we give money away, according to studies. But empathy has limits.

"Empathy, in humans at least, is often contingent upon the situation, the specifics of the situation. For example we, have less empathy with a smoker who gets lung cancer than someone who gets lung cancer without any smoking," said Frans de Waal, a psychologist at Emory University and the Yerkes Primate Center, where he studies the evolution of human behaviors through primate research. "Our empathy takes into account whether we feel this person was responsible or not responsible for the situation they are in."

"If people see this outcome as the result of an intentional action on the mother's part, or are making a moral judgment about her, then they may not empathize with her, and I would expect them to be much less interested in or enthusiastic about helping," said Georgia State University  researcher Sarah Brosnan, who studies social behavior and cognition in non-human primates.

"We cannot have rampant empathy with everybody all the time because we would go under, psychologically, if we did that," de Waal said during a telephone interview.

And helping others can be costly, or at least it was for our ancestors.

"People to have tendencies to help and rescue, but they also guard against getting exploited," Kruger said. "If people were always eager to help with other people's children, they would end up with less of their own, in the ancestral environment."

Think of the cuckoo bird, which lays its eggs in other birds' nests. "The cuckoo exploits the parental behavior of other birds and cuckoo chicks even actively push the other chicks out of the nest so they get more food for themselves," Kruger said. "There is an evolutionary arms race between the cuckoos who developed increasingly effective ways of tricking the other birds, and the other birds' ability to recognize cheaters."

Helping family

Close friends of Suleman might open their arms.

"Helping behavior is most common between friends or family," said Brosnan, adding that monkeys are more likely to bring food to kin than to familiar individuals and to familiar individuals compared with strangers.

Even mice do it, at least on a simple level. A past study found mice that observed kin (or mice they recognized) in pain have a stronger pain response themselves. But after viewing stranger mice in pain, the mice showed no such increase in their pain response, de Waal said, suggesting these mice feel empathy for their kin.

"The human in-group is not, as that of other animals, normally restricted to those who are strongly genetically similar to ourselves (our kin), but is commonly extended to include co-residents and other people with whom one associates or identifies closely," Knight told LiveScience, adding that we might be more likely to help out a neighbor than someone suffering from, say, famine in Darfur.

In a study published in a 2006 issue of the journal Personality and Social Psychology Bulletin, participants felt empathy for others in distress, such as those who needed financial help, regardless of the group they were in. But when it came to actual help, the participants only leant the helping hand if the distressed other was a member of their "in-group," which included culturally-defined groups.

When another individual is part of our in-group, say a family member or close friend, we also often cut them more slack in our moral judgments.

"We are willing to interpret the concepts of justice and fairness more generously when it comes to our children than to strangers, whose behavior we tend to judge on a strictly egalitarian basis," Knight said.

Our guts are also involved. "I think that we decide this stuff based on what our emotions tell us," said Tara Ceranic, an assistant professor of business ethics at the University of San Diego. "We get these things that in research they call affective twinges, but we would call them gut feelings. And those gut feelings kind of lead us to our judgments."

Lure of babies

While many people might be outraged at the mother's decision to risk having so many babies, these same individuals could be having their heart strings pulled by the infants themselves.

"There's an enormous attraction to infants of our species to the point that another thing that kicks in here that has little to do with empathy is that there's a vulnerable member of our species and people have a tendency to try to take care of it," de Waal said.

Any mom knows the mother-baby link feels hardwired, and researcher supports that notion: Past studies have shown the hormone oxytocin might be a contributing factor in triggering a mother to care for her infant.