One of the central principles of raising kids in America is that parents should be activel

y involved in their childrens education: meeting with teachers, volunteering at school, helping with homework, and doing a hundred other things that few working parents have time for. These obligations are so baked into American values that few parents stop to ask whether theyre worth the effort. Until this January, few researchers did, either. In the largest-ever study of how parental involvement affects academic achievement, Keith Robinson and Angel L. Harris, two sociology professors at Duke, found that mostly it doesnt. The researchers combed through nearly three decades worth of surveys of American parents and tracked 63 different measures of parental participation in kids academic lives, from helping them with homework, to talking with them about college plans. In an attempt to show whether the kids of more-involved parents improved over time, the researchers indexed these measures to childrens academic performance, including test scores in reading and math. What they found surprised them. Most measurable forms of parental involvement seem to yield few academic dividends for kids, or even to backfire(适得其反)— regardless of a parents race, class, or level of education. Do you review your daughters homework every night？ Robinson and Harriss data show that this wont help her score higher on standardized tests. Once kids enter middle school, parental help with homework can actually bring test scores down, an effect Robinson says could be caused by the fact that many parents may have forgotten, or never truly understood, the material their children learn in school. While Robinson and Harris largely disproved that assumption, they did find a handful of habits that make a difference, such as reading aloud to young kids(fewer than half of whom are read to daily)and talking with teenagers about college plans. But these interventions dont take place at school or in the presence of teachers, where policy makers have the most influence — they take place at home. Comment 1: Basically the choice is whether one wants to let kids to be kids. Persistent parental involvement and constantly communicating to the kids on what the parents want consciously or unconsciously would help the kids grow up or think like the parents sooner than otherwise. Comment 2: It also depends on the kid. Emotional and social maturity have a lot to do with success in college and in life. Some kids may have the brains and are bored by high school, but that doesnt mean they are ready for college or the work place. Comment 3: The article doesnt clearly define " helping" , but I understood it as actually assisting children in the exercises(e. g. helping them to solve a math problem)and/or reviewing their work for accuracy rather than simply making sure theyve completed their work. I think the latter is more helpful than the former. I would also certainly hope that no study would discourage parents from monitoring their childrens performance!

The word "they"(Para. 1)refers to______.

A．values

B．obligations

C．studies

D．principles