Oddly Wired
← all facts
persuasion

You eventually trust a source you once thought was lying.

A 1951 study found that persuasive messages from unreliable sources become more convincing over time.

You tend to disconnect the message from the source as your memory fades. The fact remains in your head, while the warning that it came from a liar disappears.

Your beliefs often survive by forgetting where they came from.

Where this comes from

Study
Hovland and Weiss, 1951, Sleeper Effect
What the check found
While this is a foundational study, the 'sleeper effect' is famously difficult to replicate and is highly sensitive to the specific experimental design and the nature of the message.
Confidence
Solid, with limits
persuasionmemorycredibility

Related

One of these every day, and every one names the study it came from. When a finding is contested, it says so.