for more i'm joined from chicago by david figlio, the professor of social economics, and the directorf the institute for policy research. david good to have you with us. every quhield born in florida over a 11 year period and it found that bigger babies did better all around. some of your figures, you estimate that a ten pound baby will average 80 points on the sat than a six pound baby. is the connection that direct? >> yeah, we don't know exactly what's going on behind the scenes with birth weight yet but we do know a fair amount now. it seems no matter how big the baby is, it looks like a little bit more weight is always a good thing. and that's true for doesn't matter if you are white, african american, latino, educated, less educated, the same is for everybody. >> eight pounds babies did better than seven pound babies and so on. but on the other hand you have found that it's not determinative. nature can -- nurture can overcome nature? >> it's also the case that the more advantaged you have from a neonatal perspective about more you do better in life. the two add up together. >>