Sapolsky emphasizes that neural plasticity is the mechanism by which the brain continuously remodels itself in response to experience. Rather than being static, neural circuits adapt dynamically through changes in synaptic strength, dendritic structure, and even the formation of new connections. For instance, experiences that repeatedly expose individuals to stress can lead to long-lasting modifications; stress hormones like cortisol not only influence immediate reactivity but also reshape brain regions such as the hippocampus and prefrontal cortex. These regions may undergo changes in dendritic spine density, which in turn affects memory, decision-making, and emotional regulation.

Conversely, positive experiences—like learning a new skill or engaging in rewarding social interactions—can strengthen neural pathways through processes such as long-term potentiation. This phenomenon facilitates better communication between neurons, enhancing memory and cognitive function. Sapolsky uses these examples to illustrate that our behaviors are not solely the product of hardwired genetic instructions but are also a continual negotiation between our biology and life experiences. Ultimately, neural plasticity underscores the potential for both resilience and vulnerability in the face of life’s challenges, implying that interventions, be they environmental or educational, can reshape our neural architecture and, by extension, our behavior.