Personality traits may drive our ideas about fairness and sharing

Disputes over fairness can create conflict. Families squabble over inheritances, societies polarise around the question of how to distribute wealth fairly, and nations become mired in territorial quarrels.

Many of these disputes stem from different perspectives people have on fairness. In new research, we found people’s ideas about fairness may stem from their personality traits.

No universal rule for sharing

Many disputes over fairness stem from the fact there isn’t a single universal moral solution to sharing a resource. Instead, there are several commonly used and widely acceptable moral stances, or norms.

Consider dividing an inheritance among siblings. Under the “norm of equality”, the inheritance should be split equally among them, regardless of any other information.

By the “equity norm”, however, a sibling in dire economic need should receive a larger share. By the “indirect reciprocity norm”, a sibling who has done more to take care of their parents while they were ill deserves a greater portion of the inheritance.

Individuals may disagree in good faith about which of these norms should guide the division of the inheritance.

More than selfishness

Previous research has shown that, in situations where multiple norms can be applied, individuals gravitate toward norms that best serve their economic interests.

But is this the whole story? Do people just select norms to serve their momentary interest? Or might they also have stable preferences for particular norms, even when they have no personal stake?

Read more: What do children think of economic inequality? We did an experiment to find out

In our work at the Decision Neuroscience Lab at the University of Melbourne, we shed light on these issues in two new studies. In the first, we developed a new way to measure the relative importance individuals give to different fairness norms. In the second, we related these measures to personality traits.

The ten-dollar question

To measure the importance individuals assign to different norms, we asked participants to make moral judgements of how people chose to share $10 in a simple game. Our participants rated different sharing behaviours on a scale from “morally good” to “morally bad”.

The participants showed prominent differences in how they judged different sharing behaviours. Most participants judged even-handed sharing (dividing the $10 equally) as more moral than more generous sharing (giving away more than they kept), but some did the opposite.

Some participants were quite harsh in their judgements of low sharing (such as keeping $9 and giving only $1 to one’s partner), whereas others were more accepting of such behaviours.

To describe these differences, we mathematically derived a set of scores for each individual, where each score reflected the importance they place on a different fairness norm.

Why should personality matter?

Personality traits describe characteristics of individuals that are relatively stable over time, and also persist across situations. In our research, we looked at the set of personality traits described by the Big Five framework which include: extraversion, agreeableness, openness to experience, conscientiousness, and negative emotionality.

Read more: Psychology by numbers: a brief history of personality tests

In some situations, most individuals behave in a similar way regardless of their personality. Almost everyone is likely to agree it is morally wrong to murder an innocent person.

In other situations, there will be individual differences in behaviour that do not systematically relate to personality differences. Residents of an apartment building will reliably press different buttons in the lift, but each person’s choice is determined by where they live.

However, many situations produce individual differences in behaviour that reveal people’s personalities — such as how they respond differently to stress, good news, a major life change, and so on. So, why might judging the behaviour of others be one of these situations?

First, there are robust individual differences in the importance people assign to fairness norms in moral judgements. Second, previous research has demonstrated that agreeableness in particular predicts adherence to fairness norms in several sharing situations.

Agreeableness is thought to capture kindness, politeness and compassion when dealing with others. How agreeableness is connected to fairness-related moral judgements of other people has not been studied before.

One might expect a kind, polite and compassionate person to be more forgiving and tolerant when judging others. On the other hand, agreeableness predicts higher adherence to fairness norms, so perhaps a polite and compassionate person would be highly sensitive to perceived unfairness, and thus judge the perpetrator of the unfairness more harshly. We hypothesised the latter to be the case.

How do personality traits relate to importance people assign to fairness norms?

For our second study, we measured agreeableness alongside other personality traits (including extraversion, conscientiousness, negative emotionality, and openness) using a reliable and well-validated questionnaire. We then examined associations these personality traits had with moral judgements in our sharing game.

Our findings supported the idea that agreeable individuals would judge abuses of fairness norms more harshly – and provided no support for the idea that agreeable people would be forgiving and tolerant when judging others that abuse fairness norms. Agreeable people may still be more forgiving when they are affected by norm abuses themselves, but do not seem to be forgiving on other people’s behalf.

We found people who scored highly on the traits of conscientiousness, openness and extraversion also made harsher judgements. These findings were somewhat surprising to us, so we recommend future studies to further investigate why this is the case.

Do conscientious people have a stricter understanding of fairness norms, or are they more diligent when rating the behaviour of others? Are extraverts more sensitive to abuse of some moral norms because they are more sensitive to social rewards and punishments than introverts? Do highly open people have a more confident understanding of moral situations? Further research is needed to get to the bottom of these questions.

More tolerance for moral plurality

What do these findings mean for conflicts around fairness that we encounter in our everyday lives? At least some of these conflicts likely occur because of differences in the importance individuals assign to different fairness norms.

Revealing these differences cannot settle disputes, but it may help us better understand moral plurality, and have a more tolerant approach to differences in perspective when negotiating fairness in our everyday lives.

Read more: Coronavirus and you: how your personality affects how you cope and what you can do about it