Getting out of hand: niche construction theory and a multiplicity of handedness

Human handedness shows a stable population-level bias toward right-hand preference, yet this pattern cannot be fully explained by genetic inheritance alone. In this commentary, we argue that niche construction theory provides a framework for understanding handedness as a family of dynamically constructed phenotypes that emerge through interactions between organisms and the lateralized niches they inherit and create. These niches include cultural norms, material artifacts, technological practices, and symbolic representations that can shape, stabilize, suppress, or reinterpret hand preference across development and history. From this perspective, handedness may seem to get "out of hand" when observations across these domains accumulate without sufficient theoretical constraint. Niche construction theory helps tighten this problem by situating such observations within inherited and constructed lateralized niches, suggesting that the question of how many handednesses exist depends on how those niches are individuated and studied. Rather than proposing a fixed universal taxonomy, we suggest that handedness is best understood as niche-specific, historically contingent, and shaped by multiple interacting inheritance systems.