Yes, nature AND nurture, it is no longer a question of either/or.
Studies of identical twins separated at birth, for example, seem to suggest that the truth is pretty much half way between the two poles; that is to say, personality is a combination of both genetic determination and environmental influences. It can’t be a stretch to understand that extremely complex behaviors can be inherited. A spider, for example, has a very small brain indeed, and yet, without any schooling, it is able to spin the most elaborate webs, adapting the overall design to random placements of tree branches and garden furniture. Anyone who has been present at a birth will recognize that a newborn child is possessed of its own unique musicality and is already pursuing a well developed individual agenda. There are urges and appetites, qualities and handicaps that will follow it to the end of its life.
How ironic then that the most important of all the characteristics bestowed by a baby’s genes is the ability to adapt to a complex, changing environment. And how fascinating that all these environmental influences will accumulate and express themselves in systems of belief and behavior.
Not surprisingly, these two components of human character correspond closely to the two contrasting approaches that actors take in creating a character. Some actors intuitively work their way into the core through the musicality of their character. They are the masters of transformation and theatricality. Others take a more analytical approach and develop their character as a system of beliefs acquired during its lifetime. They are the masters of observation and believability.
Great actors combine both approaches.