Dopamine, Our Motivator - Debunking Free Will #1

Someone's personality is their identity. How people take decision is largely dependent on what their personality is, i.e. if they are shy, agressive, extrovert, introvert etc. So if your personality is controlled by factors that you have no control over, that suggests that the decisions you make are not under your control either, at least not completely. I'll now try to explain you how your personality is determined not by your decisions but factors that you have no control over. So here I won't be able to cover as to how you don't have a free will at all. But I should be able to convince you that your decisions are laregly determined by agencies/factors that you have no control over.

Also, I'd like to thank Matt Ridley, who wrote the book "Genome", from which most of the following knowledge has been taken.

Dopamine 

Dopamine is a chemical presnet in neural pathways. It helps in communication between neurons. Dopamine is the motivational chemical of our brain. The activities we do, releases certain ammount of dopamine in our brain, depending on what that activity is, amount of dopamine released varies. Activity that releases more dopamine, gives us more pleasure and vice versa. All our motivations have the ultimate goal of releasing more and more dopamine in our brain, which is what makes drugs addictive. 

Excess of dopamine makes people adventurous, it makes them explore more unique things. While shortage of dopamine makes people lack motivation, to do even the slightest interesting thing.

Amount of dopamine also effects your speed of activities, shortage results in indecisive and frozen personality, whose extreme example is the Parkinson's disease. 

So this is how dopamine determines your personality, now let's see what determines dopamine. If the activity of dopamine is not under your control, this should suggest that we have no control over our motivations, or at least we don't have as much control as we think we have.

A gene named "D4DR" present on the 11th chromosome codes for the receptor of dopamine. The length of this gene varies from person to person. The larger the gene is, the less responsiveness to dopamine that person has, and vice versa. Which means if a person has short D4DR gene, then that person is content with small doses of dopamine, and doesn't seek more and more dopamine, making him less adventurous. And if a person has large D4DR, he needs more dopamine to feel content. Which means he will seek different ways to release more and more dopamine releasing activities, making him very adventurous.

So this is how a gene decides what your personality will be and with that it also determines what you decisions will be. Let's sum it up with an example - let's say we take two hypothetical people X & Y who had 100% same experiences throughout their life, everything about them is same, to such an extent that they are a copy of each other. But X has short D4DR while Y has large D4DR. Now if you ask same set of questions to both of them, regrading being adventurous, and how content they are with what they have etc. they both will give you different answers. X will be content with small things he has, he won't be very adventurous, while Y will be the opposite of that, although they are practically the same person.

This was just about dopamine. There are numerous more neurotransmitter that affect your decision making process, ultimately determined by your genes.

If your genes, which are absolutely out of your control, decide whether you will agree for an adventure trip with your friends or not, do you really have a free will?