by Kimberley Watson, PhD, PMP

The age-old debate of nature versus nurture has somewhat fizzled out. Most researchers now agree that human temperament is slightly less than 50% due to genes, and the rest due to environmental factors (Park, 2013). Thus, our predisposition for how we navigate the world is a sum of our DNA and the environment in which we were raised.


I like to explain it like this. We are formed in the womb chock full of DNA – think of it like a clump of clay with DNA mixed in. Then, we’re born into an environment. Our experiences in childhood are like water running across that DNA-filled clay. If enough water runs in the same place, you get grooves that are shaped by the water and the substances contained within the clay. Those grooves are your traits. Roll forward into adulthood and those traits – which were pretty well formed by the age of 12 and nearly indistinguishable from adulthood by age 16 (Allik, Laidra, Realo, & Pullmann, 2004) – are still there. When experiencing any environment as an adult, it’s as if water is running over your temperamentally-grooved clay. When water runs over any surface, it tends to run in the grooves.


Remember, though, water can be diverted. That’s what behavior modification is – like diverting water.


Also, although our innate traits are set pretty early in life, new research supports the phenomenon of neuroplasticity. This acknowledges that our brains remain malleable throughout our lifespan (Bullerdick, 2013). And for most of us, that’s really good news. Especially since researchers at the University of California, Berkeley determined that personality usually changes for the better as we age (Srivastava, John, Gossling, & Potter, 2003).


I know I am really glad I’m not the exact same person I was 30 years ago. But there are parts of me that span back to my childhood that have stayed consistent and I’m glad they have. For instance, the fact that I’ve always been a fighter and somewhat of a workaholic served me well during my years as a single mom and subsequently when completing a PhD in psychology while working full-time.


So, what parts stay the same and what parts change? Greater minds than mine are still (and probably will be for a long time) sorting that out. But, I have a basic theory.


Think back to my analogy of the formation of our traits as water running over DNA-filled clay. Now think of the Grand Canyon. That ginormous hole was formed over millions of years by water running over its surface. The truth is that it is still changing every day as more water runs through the Colorado River at its basin. I liken those continuing surface level changes to neuroplasticity because I have seen through research and personal experience how remarkably malleable humans are.


But, if you wanted to radically change the contours of the Grand Canyon’s deep grooves, transformation would only come with Biblical level natural disasters or some sort of explosion. For humans, I believe those types of radical changes are possible and can be accomplished through devastating rock-bottom circumstances, extreme life events, and even spiritual transformation. But, for the most part, the transformations that occur in our basic innate traits over the span of our lifetime are much like the continued erosion in the Grand Canyon.


Thus, there is a basic groovy you.



Allik, J., Laidra, K., Realo, A., & Pullmann, H. (2004). Personality Development from 12 to 18 Years of Age: Changes in Mean Levels and Structure of Traits. European Journal of Personality, 18, 445-462. doi:10.1002/per.524


Bullerdick, M. Q. (2013). The Myth of the Alpha Dog. The Science of You: The Factors That Shape Your Personality, 64-67.


Park, A. (2013). Born to Be Wild. The Science of You; The Factors That Shape Your Personality, 10-15.

Srivastava, S., John, O. P., Gossling, S. D., & Potter, J. (2003). Development of Personality in Early and Middle Adulthood: Set Like Plaster or Persistent Change? Journal of Personality and Social Psychology, 84(5).

Kim Watson, PhD, PMP

Executive Advisor