The traits commonly associated with masculinity aren't neccesarily common to all men, and the traits commonly associated with feminity aren't neccesarily common to all women. Ultimately we're individuals, and yeah, there ARE very manly men, and very feminine women, but there are also manly women, womanly men, and people on every continum in between.
People argue that in general women 'tend to be' one way and men 'tend to be' another, but there is a lot of gray areas where cultural conditioning plays a huge part. After all, whether we like it or not, men are raised with different toys, different 'colours' (blue), different expectations to women. Even in a very 'equal' family, there are still factors of outside media, school, peers, etc etc.
These things probably began because women had children and it made more sense for them to do certain activities, stick close to home etc etc.... but equally, you can argue that just because something made sense back then, that doesn't mean it makes sense now. I am a woman, but I am never going to have children, I am very goal orientated, and I'm not particularly interested in other people's feelings. This doesn't make me a MAN though, I am very much a woman, I enjoy being a woman, and there are some 'womanly' things I enjoy doing.
Anyway, the point I am trying to make is that you shouldn't 'try and be a certain way' because of your gender. Any men who like to put other people first and find themselves very good at defusing tense situations, making social networks and so on, should not try and work against these traits.
Surely personal development is about making sure your positive traits are accentuated, so if you are a people person, you don't try and become a lone explorer .... but neither do you spend all day gossiping around the water cooler. Instead you can channel that into something positive and worthwhile, whether it's persuading people to volunteer for good works, or getting people involved in the local community.
Equally, if you are a lone explorer/conquerer type, then trying to become a hostage negotiator is probably a bad idea. Instead you would try and do things that benefited from those traits.
I think it's very dangerous to start straying into 'feminine energy' and 'masculine energy' and all the rest of it. For many hundreds of years 'feminine' meant submissive, quiet homemaker in lots of cultures (depending on your social class, anyway). That WAS a bad thing, and damaged many women (and men).
Sure, there is yin and yang, and balance and it's good to have a couple that compliment rather than overlap or contradict, and different people behave in different ways.... but don't say it's because you are a man, or because you are a women.
After all, a woman might be 'hysterical because she's a woman' or she might have PTSD from being raped by her husband for seven years.
A man might be 'aggressive because he's a man' or he might be angry because he was beaten by his Dad when he was a kid.
Figuring out why we are the way we are is a really important step to self-understanding... and from understanding, we can advance and improve.