Final answer:
The Decay theory posits that memories are forgotten due to the fading of memory traces over time, which differs from interference theories that focus on competing information.
Step-by-step explanation:
The Decay theory proposes that forgetting occurs because memory traces fade over time. This theory suggests that if memories are not periodically activated, they will eventually lose their strength and be less likely to be retrieved. As per the examples from studies, it's evident that both memory trace decay and interference, specifically proactive interference, play roles in memory retention. Long-term memory, contrastingly, has a much larger capacity for information storage and relies on consolidation processes for memory stabilization.