Nature or Nuture in Becoming a Therapist

     I'm struggling with the selection process for a good therapist - that is, selecting who could become a good therapist.  Is this identity nature-based or could it be more driven by outside factors?  That is - is the deep temperament of a therapist inborn or is it something that can be molded or taught?  Of course when it comes to the satisfactory counselor, techniques and special inquiries can be instructed, but I'm more referring to the master therapist and researcher.
     If we were talking about a genetic predisposition to the field, we would almost be able to track such career choices through a family genogram.  All, or at least some/most, of the family member would exhibit behavior that would lead them along a similar professional line.
     To be sure, such a project would be very unwieldy.  We must take into account the fact that children are susceptible to lessons, modeling, and behavior perhaps more than others.  Trying to separate the unadulterated behaviors from the learned ones would be quite impossible; the only route otherwise would involve either constant self-journaling or an as yet undiscovered technology along the lines of mind reading.
     Such an endeavor is only possible through the subtle art of twin, adoption, or orphan studies.  The main issue here is that our tabula rasa is not blank for long.  From the first experience on this plane, a mind is most likely significantly altered.  So it would seem that the study would have to begin almost on day one.  No outside stimuli at all.  This would lead, of course, to extreme legal penalties based on the current moral viewpoint on infant experimentation and deprivation.
     As figuring this problem out through the pathway of nature would either be impossible or, at least, controversial, we would then have to funnel our energies through some type of nurture studies.  The question here would be:  Can we CREATE a master therapist?  The final result, were it a success, would have to be repeatable.  This involves some type of formula or quasi-formula of actions.  This view is pretty Skinnerian.
     I find that the selection process between two points tends more to be explained better through some combination of those two points, rather than an extreme on either end.  It is very likely that a certain person has the core, rough characteristics that would yield a good master therapist.  That being said, that person would need proper instruction (or some kind of outside motivation - positive or negative) in order to harness the ability afforded him through his genes.  Just as clay can be formed into beautiful pottery by hands yet cloth or bubbles cannot.
     The next step here would be to identify those traits that create a master therapist.  The next stop thereafter would involve finding hereditary lines with those traits.  An important note here is to understand that not everyone in that line would go into the field.  There are many other very satisfactory professions (e.g. intelligence services, customer services, etc.) for those who naturally show the qualities of Rogers.  After these steps, the big jump would be to create a curriculum that would yield near-perfect master therapist candidates.  Not an easy job.
     The end answer is simple.  But first, what is the question?  It is not, with nature and nurture combined, one of creating a master therapist.  An end result of this process almost assures us of this.  The question anew is: Can we create master therapists from ANYONE?  to this, my simple answer is a simple no.