Would you break the law for your family?

In the weeks leading up to 12-year-old Rebecca Sedwick’s suicide in Florida this fall, she was viciously attacked online by other adolescent girls, who told her she was ugly and urged her to “drink bleach� and kill herself. Then, after Sedwick jumped to her death from an abandoned silo, a shocking post appeared on the Facebook page of one of her harassers. “Yes IK [I know] I bullied REBECCA nd she killed her self but IDGAF [I don’t give a (expletive)].�

Appalled by the ghastly indifference of the message, the local sheriff arrested the 14-year-old, charging her with aggravated stalking. The girl’s parents quickly came forward to insist that their daughter’s Facebook account must have been hacked. She couldn’t have posted that message, the parents said, because they carefully monitored her social media interactions.

“I would check her Facebook every time she would get on it,� the girl’s mother told ABC News.

Maybe the posting really was written by someone else. But it’s also possible the parents lied to protect their daughter, and if they did, their action raises vexing questions about loyalty and responsibility. Is it OK to lie or break the law to help a close relative?

Among non-human primates, kinship is the primary determiner of whether to cooperate or compete with others. But humans have some unique social constructs: devotion to the state and to society, empathy for victims and a belief in trying to prevent further victimization. These factors can complicate decisions.

Consider the 2011 trial of Casey Anthony, who was charged with murdering her 2-year-old daughter Caylee. One piece of evidence against Casey, who was ultimately found not guilty of the murder charge, involved a search that had been performed on her computer shortly before Caylee’s death. Someone had used the computer to search for “how to make chloroform� and “neck + breaking.�

Casey’s mother, Cindy Anthony, took the stand to insist that it was she, not her daughter, who had entered those search terms. The prosecutor presented evidence based on time sheets and computer logs from the mother’s employer that she was at work at the time the searches were performed at her home, and therefore couldn’t have done them. But Cindy Anthony stuck to her story.

Was she lying to protect her daughter? And if so, should we celebrate her or blame her for doing so?

Sometimes societal bonds prove stronger than family bonds, as in the case of the self-proclaimed Unabomber, Ted Kaczynski, who killed three people and injured 23 with letter bombs he sent to protest the increasing reach of technology. He was apprehended after his brother David recognized the style and themes of the letters and alerted law enforcement officials to the possibility that Ted was responsible, an act that resulted in Ted’s arrest. David gave his million-dollar reward to the families of his brother’s victims, making it clear that he had not stepped forward to claim a reward but rather because he felt it was the right thing to do.

The legal system is ambivalent about whether a person must choose criminal justice over a family member. In most states, a person cannot be compelled to testify against a spouse, but can be if the case involves any other relative. This is odd in a way because spouses don’t share genes in the way other relatives do.

For me, a particularly fascinating case of conflicting loyalties is that of Pavlik Morozov, a boy in Stalin’s Soviet Union. Young Pavlik, at least according to the official story, was a model citizen, an ardent flag-waver and fervent patriot. In 1932, he chose state over family, denouncing his father for supposed black-marketeering. Pavlik’s father was arrested and executed, but that wasn’t the end of the story. Soon after, the boy was killed, allegedly by relatives who felt his loyalties were misplaced.

The regime’s propagandists embraced the story. Statues were erected to the young martyr who did his duty to the revolution. Poems and songs were written; schools were named for him. An opera was composed, a hagiographic movie was made about his life, and he became an icon for schoolchildren, a lesson about what constitutes the right choice.

But what counts as a correct choice can look very different in different cultures, or even to different people in the same culture.

As Pavlik’s story emerged, Stalin was told about the boy. And what was the response of the man most benefiting from such fealty to the state? Was it, “If only all my citizens were that righteous; this lad gives me hope for our nation’s future�?

No. According to historian Vejas Liulevicius of the University of Tennessee, when told about Pavlik, Stalin snorted derisively and said, “What a little pig to have done such a thing to his own family.� And then he turned the propagandists loose.

Robert M. Sapolsky is a professor of neuroscience at Stanford University and the author of “A Primate’s Memoir,� among other books. He is a contributing writer to Opinion.