1
99:59:59,999 --> 99:59:59,999
In a study in the 1990s,

2
99:59:59,999 --> 99:59:59,999
participants recalled getting lost in a 
shopping mall as children.

3
99:59:59,999 --> 99:59:59,999
Some shared these memories
in vivid detail—

4
99:59:59,999 --> 99:59:59,999
one even remembered that the old man

5
99:59:59,999 --> 99:59:59,999
who rescued him was 
wearing a flannel shirt.

6
99:59:59,999 --> 99:59:59,999
But none of these people had actually 
gotten lost in a mall.

7
99:59:59,999 --> 99:59:59,999
They produced these false memories

8
99:59:59,999 --> 99:59:59,999
when the psychologists conducting the
study told them they’d gotten lost,

9
99:59:59,999 --> 99:59:59,999
and although they might not remember
the incident,

10
99:59:59,999 --> 99:59:59,999
their parents had confirmed it.

11
99:59:59,999 --> 99:59:59,999
And it wasn’t just one or two people 
who thought they remembered getting lost—

12
99:59:59,999 --> 99:59:59,999
a quarter of the participants did.

13
99:59:59,999 --> 99:59:59,999
These findings may sound unbelievable,

14
99:59:59,999 --> 99:59:59,999
but they actually reflect a very
common experience.

15
99:59:59,999 --> 99:59:59,999
Our memories are sometimes unreliable.

16
99:59:59,999 --> 99:59:59,999
And though we still don’t know precisely
what causes this fallibility

17
99:59:59,999 --> 99:59:59,999
on a neurological level,

18
99:59:59,999 --> 99:59:59,999
research has highlighted some of the
most common ways our memories

19
99:59:59,999 --> 99:59:59,999
diverge from what actually happened.

20
99:59:59,999 --> 99:59:59,999
The mall study highlights how we can
incorporate information

21
99:59:59,999 --> 99:59:59,999
from outside sources,

22
99:59:59,999 --> 99:59:59,999
like other people or the news,

23
99:59:59,999 --> 99:59:59,999
into our personal recollections
without realizing it.

24
99:59:59,999 --> 99:59:59,999
This kind of suggestibility is just 
one influence on our memories.

25
99:59:59,999 --> 99:59:59,999
Take another study,

26
99:59:59,999 --> 99:59:59,999
in which researchers briefly showed a 
random collection of photographs

27
99:59:59,999 --> 99:59:59,999
to a group of participants,

28
99:59:59,999 --> 99:59:59,999
including images of a university campus
none of them had ever visited.

29
99:59:59,999 --> 99:59:59,999
When shown the images three weeks later,

30
99:59:59,999 --> 99:59:59,999
a majority of participants said that
they had probably or definitely

31
99:59:59,999 --> 99:59:59,999
visited the campus in the past.

32
99:59:59,999 --> 99:59:59,999
The participants misattributed information
from one context––an image they’d seen—

33
99:59:59,999 --> 99:59:59,999
onto another––a memory of something
they believed they actually experienced.

34
99:59:59,999 --> 99:59:59,999
In another experiment, people were shown
an image of a magnifying glass,

35
99:59:59,999 --> 99:59:59,999
and then told to imagine a lollipop.

36
99:59:59,999 --> 99:59:59,999
They frequently recalled that they saw 
the magnifying glass and the lollipop.

37
99:59:59,999 --> 99:59:59,999
They struggled to link the objects to 
the correct context––

38
99:59:59,999 --> 99:59:59,999
whether they actually saw them,
or simply imagined them.

39
99:59:59,999 --> 99:59:59,999
Another study, where a psychologist 
questioned over 2,000 people

40
99:59:59,999 --> 99:59:59,999
on their views about the legalization 
of marijuana,

41
99:59:59,999 --> 99:59:59,999
highlights yet another kind of influence
on memory.

42
99:59:59,999 --> 99:59:59,999
Participants answered questions in 1973
and 1982.

43
99:59:59,999 --> 99:59:59,999
Those who said they had supported
marijuana legalization in 1973,

44
99:59:59,999 --> 99:59:59,999
but reported they were against it in 1982,

45
99:59:59,999 --> 99:59:59,999
were more likely to recall that they were 
actually against legalization in 1973––

46
99:59:59,999 --> 99:59:59,999
bringing their old views in line 
with their current ones.

47
99:59:59,999 --> 99:59:59,999
Our current opinions, feelings, and experiences
can bias our memories of how we felt in the past.

48
99:59:59,999 --> 99:59:59,999
In another study,

49
99:59:59,999 --> 99:59:59,999
researchers gave two groups
of participants background information

50
99:59:59,999 --> 99:59:59,999
on a historical war and asked them to rate
the likelihood that each side would win.

51
99:59:59,999 --> 99:59:59,999
They gave each group the same information,

52
99:59:59,999 --> 99:59:59,999
except that they only told one group
who had actually won the war—

53
99:59:59,999 --> 99:59:59,999
the other group didn’t know the
real world outcome.

54
99:59:59,999 --> 99:59:59,999
In theory, both groups’ answers should
be similar,

55
99:59:59,999 --> 99:59:59,999
because the likelihood
of each side winning

56
99:59:59,999 --> 99:59:59,999
isn’t effected by who actually won—

57
99:59:59,999 --> 99:59:59,999
if there’s a 20% chance of thunderstorms,
and a thunderstorm happens,

58
99:59:59,999 --> 99:59:59,999
the chance of thunderstorms
doesn’t retroactively go up to 100%.

59
99:59:59,999 --> 99:59:59,999
Still, the group that knew how the war
ended rated the winning side

60
99:59:59,999 --> 99:59:59,999
as more likely to win than the
group who did not.

61
99:59:59,999 --> 99:59:59,999
All of these fallibilities of memory 
can have real-world impacts.

62
99:59:59,999 --> 99:59:59,999
If police interrogations use leading
questions with eye witnesses or suspects,

63
99:59:59,999 --> 99:59:59,999
suggestibility could result in incorrect 
identifications or unreliable confessions.

64
99:59:59,999 --> 99:59:59,999
Even in the absence of leading questions,

65
99:59:59,999 --> 99:59:59,999
misattribution can lead to inaccurate 
eyewitness testimony.

66
99:59:59,999 --> 99:59:59,999
In a courtroom,

67
99:59:59,999 --> 99:59:59,999
if a judge rules a piece of evidence 
inadmissible

68
99:59:59,999 --> 99:59:59,999
and tells jurors to disregard it,
they may not be able to do so.

69
99:59:59,999 --> 99:59:59,999
In a medical setting, if a patient 
seeks a second opinions

70
99:59:59,999 --> 99:59:59,999
and the second physician is aware of the 
first one’s diagnosis,

71
99:59:59,999 --> 99:59:59,999
that knowledge may bias their conclusion.

72
99:59:59,999 --> 99:59:59,999
Our memories are not ironclad 
representations of reality,

73
99:59:59,999 --> 99:59:59,999
but subjective perceptions.

74
99:59:59,999 --> 99:59:59,999
And there’s not necessarily
anything wrong with that—

75
99:59:59,999 --> 99:59:59,999
the problems arise when we treat
memory as fact,

76
99:59:59,999 --> 99:59:59,999
rather than accepting
this fundamental truth

77
99:59:59,999 --> 99:59:59,999
about the nature of our recollections.