Skill decay is the gradual loss of a capability when it is not used often enough. In cyber security, this can affect analysts who rely heavily on automation, playbooks, or AI-generated recommendations and stop practicing core tasks such as log inspection, threat hunting, rule tuning, and incident triage. Over time, people may become slower at spotting anomalies, explaining decisions, or recognizing when a tool is wrong.
It matters because attackers exploit weak human judgment as well as technical gaps. If staff only approve machine output, automation bias and cognitive offloading can hide subtle indicators of compromise. Defenders reduce skill decay by rotating manual tasks, running no-tool exercises, requiring source tracing and second review, and testing whether analysts can still work without assistance. The goal is not to avoid automation, but to keep human expertise current and verifiable.