单选题 Brothers and sisters fight, but when the bickering evolves into physical or emotional abuse, it's bullying. Ordinary arguments over toys and who gets the front seat are one thing, but a recent study from researchers at the University of New Hampshire reports that aggression between siblings can escalate into bullying, and that young victims can be harmed in the same way as those who are threatened by peers on the playground. In fact, the study authors say, being bullied by a brother or sister was linked to worse mental-health outcomes for kids and adolescents, similar to those associated with being bullied by unrelated kids in the schoolyard. The new study, published in the journal Pediatrics, involved thousands of children and adolescents throughout the U.S. and found that those who were physically assaulted, had their toys stolen or broken or endured emotional abuse that made them feel frightened or unwanted by their sibling had higher levels of depression, anger and anxiety than those without these experiences. In order to study any differences between the effects of sibling bullying and those of being threatened by an unrelated bully, the researchers compared the effects of aggressive behaviors, such as physical violence, breaking or taking toys or belongings, and abuse, like name-calling or mocking, originating from siblings with those coming from children's unrelated peers. They concluded that as far as mental-health effects are concerned, the relationship that the victims had with their bullies didn't seem to matter. The findings showed that sibling bullying had the same association with increased anxiety, depression and trauma as peer aggression. That's an eye-opening result since most parents—not to mention the public—have a higher tolerance for fighting and even threatening behavior among siblings than they do for other social relationships. Sibling fighting is often dismissed, seen as something that's normal or harmless. Some parents even think it's beneficial, as training for dealing with conflict and aggression in other relationships. But when does that normal quarreling evolve into something more? Parents may unknowingly play a role in escalating some sibling fighting into abuse, John V. Caffaro, a clinical psychologist and co-author of Sibling Abuse Trauma, told the New York Times. If parents allow children to continuously fight and confront each other in aggressive ways without intervening, or if they play favorites and label children as "the smart one" or the "the quiet one," that may lead to more unhealthy competitiveness between siblings that develops into abuse. Caffaro said that since violence between siblings is one of the most common types of familial violence, aggression with the intent to physical hurt or humiliate a brother or sister should be taken seriously, and quashed.

单选题 The word "bickering" (Line 1, Para. 1) is closest in meaning to _____.

单选题 The new study published in Pediatrics shows that _____.

单选题 After comparing the effects, the researchers found that_____.

单选题 It can be learned that some parents actually _____.

单选题 Caffaro would most probably agree that_____.