How Important Are Brothers and Sisters?

Kids often look up to their older brothers and sisters -- both literally and figuratively -- but now research suggests that sibling relationships might be more important than previously believed. Several studies conducted during the past two decades reveal that an older sibling's actions can be more influential on a younger child than those of that child's parents. Older siblings have been found to influence whether a younger sibling picks up bad habits, succeeds in academics, or even gets pregnant. For example, a 2004 study found that people are 25 percent more likely to smoke cigarettes and 36 percent more likely to drink alcohol if an older sibling does so, regardless of the habits of their parents. And according to a 2009 survey, a young woman is five times more likely to have a baby if her older sister has already become pregnant. Lastly, a 2014 study found that an older sibling's academic support translates to school success for younger siblings, especially in families in which the parents face disadvantages, such as language barriers.

All about brothers and sisters:

• They might deny it, but most parents actually do have favorite children, according to a University of California study.
• A University of Leipzig study found that first-born children are often the most intelligent, but birth order appears to have no bearing on personality.
• Middle children are more likely to develop meaningful friendships outside of the family and tend to be the first to head out on their own.