Sociopath Community

It is aggressive but in a positive sense. It shows that you are listening, you are not afraid and got confidence. If you are not afraid and got confidence, it shows that you can handle the situation and that you are the person your client is looking for. 

There is a difference between looking in the eyes and staring at someone in the eyes. It is okay to look away from time to time at the stuff you are talking about. Looking too much in the eyes becomes starring and that is creepy.

Communication is important in business. Good communication is efficient work. If you know how to communicate is a positiv way, you have leadership. Leadership is not just about yelling at your employees to do this and that, leadership is how you handle things efficiently and how good you communicate with others in a positive way.

EDIT: I didn't read Legga's post before writing that, but yes, Legga is right. Try focusing on the face if the eyes intimidates you, between the eyes is a good spot (you don't directly look into the eyes and the other person think you are). Try relaxing a bit before the meeting or the phone call. Try to laugh a bit about the situation. 

I'm not sure how a sign of aggression and domination became a sign of politeness.

How often does it happen? Were you more anxious or tired lately? Lack of sleep or comfort could explain your increased nervousness.

I'm not sure when maintaining eye contact during a conversation became considered as a sign of aggression.

This is stupid, it has less to do with how long you're looking into their eyes than it has to do with your expression, and what you're saying with it. Eyes usually reflect your thoughts/feelings about that person or situation. Stare into the eyes of a lover for how long you want, that shouldn't be taken as aggression XD

I rarely get nervous, but no... I don't loose my breath.

I used to do a lot of acting, so my way of getting around old nerves issues was to play the part or role of a more confident person, putting myself into the shoes of someone who doesn't respond nervously to this sort of thing. If I needed any prior knowledge for the conversation, I'd study them like they were lines, but with notecards so that I could reference them without it having to be in a specific order.

After doing it for a long enough time, the "part" became second nature, eventually just becoming a part of me.

My old tell used to be not knowing what to do with my hands. It took so much work to get rid of that tell. An open posture shows comfort and confidence, where drawing elements toward yourself (hands in pockets, crossing arms, excessive scratching) shows insecurity, a need to defend.