A study that was recently published in the American Sociological Review found that couples who adopt children invest more money, and more time, with their kids.

"'One of the reasons adoptive parents invest more is that they really want children, and they go to extraordinary means to have them,' Indiana University sociologist Brian Powell, one of the study's co-authors, said..."

Data from 13,000 households was examined for the study, and 161 of those households were headed by adoptive parents. The adoptive parents rated better overall in variety of area - including helping with homework and parental involvement. Read more at MSNBC.com.