Most of us have noted that we choose individuals who have complimentary personality traits as our lovers and partners. We now know that many "psychological" traits, such as depression and bi-polar have deeper electro-chemical-biological roots in our physical brains. Ergo, much of who we are is due to genes, and physical results of those genes. In the debate over "nurture or nature", I lean strongly towards nature. My daughters both grew up to be very much like me, even though there was a ten year period wherein I did not see or communicate with them in any way.