"A man is a sum total of his experiences"...video in YouTube, which was shared through my LinkedIn connections. According to Newtonian mechanics, the destiny of a particle is already determined. Einstein, being a deterministic agrees when he said that, " God doesn't play dice". However, Heisenberg comes and introduces the concept of uncertainty. That is there is always an uncertainty associated with the position of the particles. Thus, the video concludes that the destiny of the particles is not predetermined and since it involves certain uncertainty, leads to "Free will".
There are some holes in that argument. First Heisenberg uncertainty principles more specifically says that it is not possible to determine the position and velocity of the particle simultaneously, in which case, he quantifies the error. If we assume that position and velocity together describe the state of a particle, then the argument in the video may seem plausible.
However, now quantum nanostructures exists that restrict the movement of the particles. In such case, although it is not possible to determine the exact state of the particle, there is a definite probability for the particle to exist in within the structure i.e in a boundary. Consider the case of tunneling effect (Tunnel Diode), the electron in the box cannot get over the energy barrier if doesn't have enough energy. However, once it acquires sufficient energy, even though this energy is less than what is required to jump over the energy barrier, it could tunnel through the barrier due to its wave nature. In either case, whether it remains trapped within the box or it exits the box by jumping over the energy barrier or by tunnelling, there exits a definite probability depending upon the energy input and the barrier. In other words, the state i.e. inside or outside the box is determined by its energy. By extension, the one who controls this energy determines the particles destiny. The probability of the particle existing within a nanostructure follows a well defined Gaussian distribution, under some conditions.
Factors that may determine an individuals destiny
Like energy which determines the particle state, genetics is one of the factors that could influence the development and maturity of a person. There are studies that find correlation between school performance and genetic predisposition. This is the case of physical performance also. For example most of the Marathon title were held by the Ethiopians. One of my friends in my Masters class was from Ethiopia and he said that it is not all Ethiopians who have the ability but only people coming from a particular tribe. This tribe happen to be a hunter-gatherer group for a very long time and have evolved to have the endurance required to survive in their environment. So, isn't that destiny of the individual determined, in a broad sense? Of course, he is still free to choose what he does, but his genetics only permits certain things...!
It is another factor, that influence the development and thought process of an individual. The development of the "free will" itself seem to be interlinked with economy or the families income. A study in UK, apparently showed that the children from poorer families tend to have some parts of their brain smaller than other kids, which affect their performance in their school. So, being born in poor family, already determines the level of academic achievement the child could achieve. Irrespective of whether he wants to or not. In other words, his destiny in a broad sense is determined. The only "free will" he/she then has is how to act in such a way to reduce disadvantage... even for that he is at a disadvantage... because it is the brain that makes this reasoning.
In the first two factors, I discussed the natural elements that affect the development. The third is environment. A child born to a poor family in a locality is more likely to involve in criminal activity (deduced based on bayesian inference), if the last two factors are true. Even if the child has reasonable intelligence and school performance, he or she could never realize his true potential if the environment is not right. As a personal case, during my 9th grade, I developed a fully herbal mosquito repeller. It was tested in the Vector Control Research Centre (VCRC) in our home town, thanks to one of my teachers who trusted me. However, everyone my parents, my school and even the scientist at the VCRC only discouraged me from further developing the product (Once I get a job one of my first work would be to fully develop that). This is an exact example of how environment could prevent one from realizing his/her full potential. The only "Free will" I had/have is to determine if I want to continue my fight or kill myself.
What if there is complete "Free Will"
Anyone who have visited Amazon would know that Amazon suggests items based on the items that you are checking. The system that does that is called a recommender system, a piece of machine learning software. Consider that there is no pattern, then the systems results would make no sense... every item would have equal probability.
Similarly, based on public sentiments, there are many studies in the world that try predict election outcomes. Isn't it how the Tories utilized the public opinion to come to power in Canada or Mr. Modi in India. If the public opinion is totally random, then it is highly likely that the results would be inconclusive.
Banking and Economy (stock prices) would also suffer. Bloomberg has a team of experts in analyzing sentiments from different source to predict stock prices. What if the opinions are random?
Similarly, if the Banks could not predict the user behaviour they could not invest and the banking will collapse.
And no boutiques for girls would stack up only pink...:)
There would be no racism, stereotypes, xenophobia, etc.
To conclude, "Free will" is bounded by the system in which it exists... Breaking the system is not always possible, as was found by Galileo, Edward Snowden and the like...!