Thesis advisor: Sara Cordes / Throughout early childhood, children learn various symbolic systems to represent abstract concepts such as quantity. Yet it is unclear how the acquisition of symbols for quantity (e.g., number words; measurement concepts of “seconds”, “minutes”… for time, etc.) may shape nonsymbolic representations of these quantities. While previous work hints at the possibility that acquiring numerical symbols refines numerical acuity (i.e., “refinement hypothesis”), these data are correlational in nature, making it impossible to assess causality. As such, experimental manipulations training the symbolic system are necessary in order to determine whether a causal relation exists. Moreover, these investigations have been limited to the domain of number, making it unclear if similar relations exist in continuous quantities, such as time and space. My dissertation tests whether the relation between symbolic and nonsymbolic abilities holds for the inherently continuous quantity of time, while also providing one of the first investigations of the refinement hypothesis outside of the domain of number. Results reveal that nonsymbolic and symbolic timing are related in childhood, both before and during formal instruction on temporal units of measurement (Experiment 1 & 2), but not in adulthood (Experiment 3). Further, I find no support for the refinement hypothesis: learning temporal symbols did not result in improved temporal acuity (Experiment 2), nor did shifting adults’ symbolic mapping of time shape temporal acuity (Experiment 3). Similarly, learning labels for surface area did not enhance adults’ spatial acuity (Experiment 4). Broader educational implications and areas of future investigation are also discussed. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.