are often the most balanced I find. They may become apparent when it comes to their dominant function, but they're quite aware and active with their other functions.
Think of that person you know that came across ESTP one way and another instant, ESFP. What makes them exercise their other functions are likely their held values! I would even say they are the most desirable and interesting people I've come across.
In theory, I have a poor dysfunctional family and each of us became fiercely individualistic and impatient. Perhaps they were raised with a close family.. who knows? There are a few theories that would provide a facility to alternate functions within their environment.
I know it's not just me that feels this way. What examples have you noticed in those "balanced" who almost transcend the MBTI model?