Memory Biases

Telescoping Effect

Definition

The telescoping effect is the tendency to misplace past events in time: important recent events feel further back than they are (backward telescoping), while old but significant events feel closer than they are (forward telescoping). Memory stretches or shrinks the timeline according to emotional weight.

Real-world example

Ask people 'how long ago did the pandemic start?' and you'll get answers ranging from 'it feels like four years' to 'it feels like last week.' The truth depends on when the question is asked, but systematic errors show up: major global events are often remembered as closer than they are (9/11, terrorist attacks, financial crises).

Janssen, Chessa, and Murre (2006) demonstrated the effect in structured surveys: Recent events (0–2 years back) get telescoped 'backward,' while events 5+ years back get telescoped 'forward.' The effect has consequences for public surveys about, say, crime victims ('in the past year, have you been subjected to...') because respondents pull events into the time window from outside it.

Supplementary perspective

The telescoping effect is one of several memory biases that together mean we shouldn't trust our own dating of events without support. Diaries, emails, calendars, and photos provide objective dating. In research, one compensates by using reference events ('before or after you moved?'), which yield more accurate answers than direct date questions.

Practical advice

Recognize

—Notice if you say 'a few years ago' about things that were yesterday – or the reverse.
—Check memories against written sources when dating matters.
—Be extra critical of the dating of emotionally charged events.

Counteract

—Use concrete anchors: 'Was it before or after I started the new job?'
—Check calendar, email, or photos for dating.
—In interviews: Use reference events instead of date questions.

Ethical use

—In surveys: Design questions to minimize telescoping (bounded windows, reference events).
—In legal testimony: Be cautious about trusting witnesses' dating without supporting documents.
—In journalism: Verify time claims against archives.