You symbolize the role you are taking by your position in relation to others.  If you stand while others sit you elevate your status or emphasize your higher position.  You wouldn't be comfortable speaking up to a giant towering over you.  Good teachers sit or kneel so that they spend much of their time at the same level as their students.  It is a mammalian response to raise one's body to dominate and lower it to humble oneself.  Don't dominate more than you intend to.

 

Encourage lateral messages (4) with posture alignment wherever you can but don't lie about it.  Be sure to acknowledge power (12) where there is a significant difference.  Neither invade nor avoid the other's personal space (25).  Equalize relations by meeting on neutral turf (30).