Working memory (WM) is a short-term memory system important for higher level cognition. WM has a limited capacity. An active removal process has been identified to clear information that has become irrelevant for present processing in order to assist with WM maintenance and WM updating processes. This thesis contains five studies that aim to investigate the nature of the inter-relationships between removal, WM, and fluid intelligence, in addition to investigating whether removal is an inhibitory process. Results indicate that WM capacity fully mediates the relationship between removal and fluid intelligence, and that removal is not an inhibitory process.