Hrm, well as a middle child I did strive to be different from my brother. I grew up disliking him because I felt I was always being compared to him. I looked at him as a geek because he was a good student. I strived to be good in sports and always gave every thing I played 110%, I hated being compared to him.

As far as the marriage thing, I was married to a first born and I did end up changing my desires to please her, very interesting.

I agree with the less dependent on the family for attention too. But maybe that's because I was gone for 5 years and didn't talk to anyone.