Final answer:
The recency effect in memory is mainly due to interference, which can be either proactive or retroactive, with retroactive interference being the primary reason for the recency effect as newer memories can overshadow older ones.
Step-by-step explanation:
We tend to observe a recency effect in memory because of four potential reasons, but the correct one in this context is (c) Interference. Interference happens in two forms - proactive and retroactive. Proactive interference occurs when old information prevents or hinders the recall of newer information. Conversely, retroactive interference happens when new information makes it harder to recall older information. This plays a significant role in why we may experience the recency effect - our more recent memories overshadow our older ones.
Student experiences, such as mixing up an old address with a new one, illustrate proactive interference, while struggling to recall an old theory after learning a new one exemplifies retroactive interference. Both forms demonstrate how current or recent memories can be more readily accessed or can interfere with recalling past events or information, contributing to the recency effect observed in our memory.