Philosophy has long been debated for its relevance to natural sciences. Drawing from evolutionary biology, I exemplify how philosophy contributed to scientific discourse, in particular to the concept of genes and traits. Rather than determining distinct traits, genes influence the plastic development of traits, especially during sensitive periods. EvoDevo further integrates philosophical insights to explore how developmental processes influence evolutionary change. I highlight the concept of heterochrony which describes temporal changes of developmental events during evolution. I argue that neuroscience could also benefit from similar conceptual scrutiny. In the paper, I discuss the expansion of the human neocortex in light of heterochrony and developmental plasticity as a key example. Plasticity allows organisms to adapt to fluctuating environments characteristic of the human cognitive niche and contributes to diversity. As an effect of heterochrony, postnatal brain development in modern humans is prolonged and the brain remains highly plastic. While periods of plasticity enable developmental variability, they also introduce the risk of neurodevelopmental aberrations, such as in schizophrenia. Schizophrenia is characterized by an abnormal prolongation of neuroplasticity due to an impaired excitatory/inhibitory balance and excessive synaptic pruning, particularly in the prefrontal cortex. This “overpruning” combined with delayed maturation may contribute to the disorder´s onset and progression. The interplay between environmental factors and neurodevelopment during sensitive periods is crucial in shaping the disease outcome. This reconceptualization challenges traditional gene-for-trait paradigms and instead advocates for a focus on developmental timing during different life stages to better understand the etiology of psychopathologies and potential intervention strategies.