Hello,   I am trying to look at the correlation between mom's weight at time of birth and her kids' weight later in life. I'm doing this by comparing a given mom's weight at the time of each of her kids' births, and their weight later on in life. I currently have my data constructed so that all siblings (same mom and dad) are paired off (so if there are four siblings in a family, there will be 6 observations of different sibling pairs). Within the data, each observation has the following variables: the ID of two siblings (ID_1 and ID_2), the mom's weight at each birth (mom_wt_1 and mom_wt_2), and the kids' weight later on (kid_wt_1 and kid_wt_2). There are several thousand observations. I am looking for a significant increase in kids' weight compared to their siblings if the mom was heavier when giving birth.   What procedure should I use to look for this correlation?   Thanks for your help! ... View more