What it is
The telescoping effect refers to misperceptions regarding time, where people may think events occurred more recently (forward telescoping), or more distantly (backward telescoping) than they actually did.
Why it happens
Although there is no scientific consensus on the bias, some researchers attribute the telescoping effect to the accessibility principle, where perceptions of time in relation to certain events depend on how accessible information is in one’s memory.
Example 1 – How long have you been smoking?
A number of research papers on the telescoping effect have explored the implications of faults in self-reporting related to public health efforts aimed at combating substance abuse. The age of onset for certain substances, which has been shown to be susceptible to the telescoping effect, is an important data point in understanding substance usage.
Example 2 – “It seems like only yesterday”
This nostalgic comment often manifests in a form of forward telescoping, whereby recalling a distant but vivid memory, the moment we’re thinking back on seems more recent than it is.
How to avoid it
On an individual level, if knowing the provenance of an event in memory is an important factor in making a decision, it’s helpful to reference data whenever possible instead of relying on your hunch in regard to when an event occurred.
From a survey design perspective, it may be worthwhile to frame questions in a way that can guide the respondent in providing an accurate response. Blind faith in taking survey responses at face value can neglect the impact of potential cognitive biases such as the telescoping effect.