Trust is important. Without the ability to trust strangers,
society would fall apart. You have to
trust that people will generally deal with you honestly, and that they will follow
through on their commitments. After all,
you do not know all the people who grow your food, make your clothes, and take
care of your money in the bank. You do
not have the time to do all of these things for yourself.
Of course, most of this trust is
implicit. You do not often think about
the number of strangers you rely on to get through your daily life.
Sometimes, though, you have to
place your trust in a stranger more explicitly.
Not long ago, I was sitting at an airport by a bank of outlets. A woman walked up, plugged in a cell phone,
and asked two of us sitting by the outlets to watch her phone for a few minutes
while she went to check her flight. She
had to trust that we would not steal her phone, and we had to trust that she
was not leaving us sitting next to a dangerous device. And in the end, our mutual trust was
rewarded.
An interesting paper that has been
accepted for publication in the Journal of Experimental Social Psychology
by Sarah Ainsworth, Roy Baumeister, Kathleen Vohs, and Dan Ariely examines
whether this kind of trust among strangers requires mental effort.
The measure of trust they used in
these studies was a behavioral economics game called the Trust Game. In the Trust
Game, participants are given $10. They
are told that they can give as much of that money as they want to their
partner. The experimenter will then
triple the amount of money given to the partner, and the partner can return as
much of that money as he or she chooses to the participant. So, if the participant elects to give $3 to
the partner, the partner will receive $9 from the experimenter.
This game requires trust. The best joint outcome for the players in
this game requires that the participant give all of the money to the partner
and requires the partner to split the proceeds.
If the participant does not trust the partner, then the participant can
choose to keep all of the money.
These researchers suggest that
trusting a stranger in this game requires overcoming a natural tendency to
avoid risk. To explore this possibility,
they overlaid an ego depletion manipulation on this study. The concept behind ego depletion is that when
people engage in a period of effortful self-regulation, they have difficulty
overcoming their habitual tendencies in the future. So, if trust requires some amount of effort,
people who first do a task that requires effort will trust the stranger less
than those who do not do this task.
In one study, participants watched
a silent video of a woman being interviewed.
Periodically, words appeared in the lower right corner of the
screen. One group just watched the
video, while a second group was told to ignore the words and to return their
attention to the woman as soon as they noticed themselves looking at the
words. This task has been used in
previous research on ego depletion.
After watching the video,
participants were given the trust game and were told they were playing with a
partner in another room. Participants
also filled out a scale that measured the personality characteristic of
neuroticism. Neuroticism is the degree
to which people tend to focus on negative outcomes and also the degree to which
they tend to experience high-arousal emotions like anxiety and anger.
In this study, participants with
low levels of neuroticism were not strongly influenced by the ego depletion
manipulation. However, those with a high
level of neuroticism gave much less money to their partner when they had to
avoid looking at the words on the video than when they did not.
The idea here is that people with
a high level of neuroticism (and particularly the aspect of neuroticism that
focuses on the strength of their negative emotions) have a tendency to fear
risk. This group wants to avoid giving
money to their partner. Only when they
have enough motivational energy will they be able to overcome that
tendency.
Two other experiments examined two
other factors that also influence people’s likelihood of trusting another
person. In one study, some participants
were told they would meet their partner after the game. In a second study, participants were given a
(fake) EEG measurement at the start of the task. Some participants were told that their
partner had a very similar EEG measurement, of the sort you would only expect
among siblings, relatives, and close friends.
The ego depletion manipulation did
not influence the amount of money people were willing to give to their partner
when they believed they would meet their partner or when they believed they
were very similar to their partner. It
did influence the amount of money that highly neurotic individuals were willing
to give in these studies when they did not think they would meet their partner
or did not think they were similar to their partner.
Putting all of this together,
then, trusting strangers sometimes requires effort. In particular, when you believe you will
never meet someone and you have no particular similarity to them, you believe
there is a risk to trusting them. The more
strongly you react to that kind of risk, the more effort you need to put in to
trust a stranger.