Are all of your memories real? - Daniel L. Schacter

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In a 1990's study, participants recalled getting lost in a shopping mall as children. Some shared these memories in vivid detail, but there was one problem: none of these people had actually gotten lost in a mall. They produced these false memories after psychologists told them they'd gotten lost and parents confirmed it. So what's going on? Daniel L. Schacter explores the fallibility of our memory.

Lesson by Daniel L. Schacter, directed by AIM Creative Studios.

In a study in the 1990s,

participants recalled getting lost
in a shopping mall as children.

Some shared these memories
in vivid detail—

one even remembered that the old man
who rescued him

was wearing a flannel shirt.

But none of these people
had actually gotten lost in a mall.

They produced these false memories

when the psychologists conducting
the study told them they’d gotten lost,

and although they might not remember
the incident,

their parents had confirmed it.

And it wasn’t just one or two people
who thought they remembered getting lost—

a quarter of the participants did.

These findings may sound unbelievable,

but they actually reflect
a very common experience.

Our memories are sometimes unreliable.

And though we still don’t know precisely
what causes this fallibility

on a neurological level,

research has highlighted some
of the most common ways our memories

diverge from what actually happened.

The mall study highlights how we can
incorporate information

from outside sources,

like other people or the news,

into our personal recollections
without realizing it.

This kind of suggestibility is just
one influence on our memories.

Take another study,

in which researchers briefly showed
a random collection of photographs

to a group of participants,

including images of a university campus
none of them had ever visited.

When shown the images three weeks later,

a majority of participants said
that they had probably or definitely

visited the campus in the past.

The participants misattributed information
from one context— an image they’d seen—

onto another— a memory of something
they believed they actually experienced.

In another experiment, people were shown
an image of a magnifying glass,

and then told to imagine a lollipop.

They frequently recalled that they saw
the magnifying glass and the lollipop.

They struggled to link the objects
to the correct context—

whether they actually saw them,
or simply imagined them.

Another study, where a psychologist
questioned over 2,000 people

on their views about the legalization
of marijuana,

highlights yet another kind
of influence on memory.

Participants answered questions
in 1973 and 1982.

Those who said they had supported
marijuana legalization in 1973,

but reported they were against it in 1982,

were more likely to recall that they were
actually against legalization in 1973—

bringing their old views in line
with their current ones.

Our current opinions,
feelings, and experiences

can bias our memories
of how we felt in the past.

In another study,

researchers gave two groups
of participants background information

on a historical war and asked them to rate
the likelihood that each side would win.

They gave each group the same information,

except that they only told one group
who had actually won the war—

the other group didn’t know
the real world outcome.

In theory, both groups’ answers
should be similar,

because the likelihood
of each side winning

isn’t effected by who actually won—

if there’s a 20% chance of thunderstorms,
and a thunderstorm happens,

the chance of thunderstorms
doesn’t retroactively go up to 100%.

Still, the group that knew
how the war ended

rated the winning side as more likely
to win than the group who did not.

All of these fallibilities of memory
can have real-world impacts.

If police interrogations use leading
questions with eye witnesses or suspects,

suggestibility could result in incorrect
identifications or unreliable confessions.

Even in the absence of leading questions,

misattribution can lead to inaccurate
eyewitness testimony.

In a courtroom,

if a judge rules a piece of evidence
inadmissible

and tells jurors to disregard it,
they may not be able to do so.

In a medical setting, if a patient
seeks a second opinion

and the second physician is aware
of the first one’s diagnosis,

that knowledge may bias their conclusion.

Our memories are not ironclad
representations of reality,

but subjective perceptions.

And there’s not necessarily
anything wrong with that—

the problems arise when we treat
memory as fact,

rather than accepting
this fundamental truth

about the nature of our recollections.