If I'm understanding the author's premise, a single born human is already cast from a mold that human had no choice in, gets exposed to treatment of which they have no control over, in an environment they have no control over, so that when they are an adult they are essentially an unchangable program that will react to life's events in one specific way until death. This includes events that adult goes through that changes them, those too were predicated on how they were essentially programmed from DNA and childhood.

However, we has humans, can shape the conditions the next generation will encounter which would influence that generation's programming. So there is still allowance in the author's premise that would allow humanity to grow and change even if the individual can't in their lifetime.

There is nothing fundamentally free with humans acting according to their biological desires.

Prior generations of humanity can change the conditions that those biological desires manifest, altering those subsequent generation's behavior.

A perfect example of this is that you, yourself, likely haven't gone to war and killed anyone for a meal in your lifetime. Prior generations addressed increasing the food supply beyond hunting and gathering. So today your biological impulses don't require murdering other humans for you to eat.