Feel the same about sisters.

I have this suspicion that it makes a lot of things easier as your forming years are so important.

I am really convinced that there must be beneficial factors to having a brother and a sister compared to having one brother when male or having one sister when female.

There must be research on this. But I never heard anyone mention it.

[edit]

These are a few possible links to possible papers:
http://www.nursingschools.net/blog/2...bout-siblings/

I doubt most of these are really solidly established. But they are the type of thing I am interested in.

I guess even more importantly is being an only child or not having two parents.