Children have sense of fairness by age of seven

By Roger Highfield, Science Editor
Last Updated: 6:01pm BST 27/08/2008

Children develop a sense of fairness by the age of seven, according 
to a new study.

In research that should help to chart the origins of human social 
life, morality and culture, a team has pinned down when humans learn 
to share.

Children as young as seven are just as likely as adults to do the 
right thing by their friends, in contrast to kids between three and 
four, who are almost universally selfish, reports the study carried 
out at the Universities of Zurich, Switzerland, and Erfurt, Germany.

What is fascinating about the study in the journal Nature, led by 
Prof Ernst Fehr, is that children do not simply become more generous 
but develop a clear sense of what is fair and what is not.

This development, which has never been shown to occur in other 
species, "may be an important reason for the unique cooperative 
abilities of humans," he says.

Unlike animal and insect societies, human societies are based on a 
detailed division of labour and cooperation in large groups of 
genetically unrelated individuals.

Human cooperation "differs spectacularly", he says, "probably because 
humans also have a preference for others' well-being."

But the way a sense of fairness develops is not well understood and 
Prof Fehr hopes that his new work will help shed light on why humans 
are the champion cooperators of the natural world.

In the study done with 229 children between the ages of three and 
eight at the University of Zurich Prof Fehr and Dr Helen Bernhard of 
Zurich, working with Dr Bettina Rockenbach of the University of Erfur 
carried out experiments to find out.

Around half of the children made their decisions in the knowledge 
that the other child was from the same nursery school, kindergarten, 
or school.

The remaining half of the children knew that the other child was from 
a different nursery school, kindergarten, or school.

Children were placed in pairs, and one of them was given the choice 
between two options, such as "one for me, none for you" versus one 
sweet each.

Sharing was with an anonymous other child (who changed from 
experiment to experiment, so they did not fear retaliation if they 
were mean), though they knew whether that child was from the same 

Although often the child doing the choosing would receive one sweet 
regardless of their choice, many of the younger children (aged 3-4) 
still chose to deprive their fellow partner of a sweet.

There is a reluctance to share and "self-interest is the dominant 
type of behaviour", which matches that seen in experiments with our 
close relatives, chimpanzees.

But by the time the children are around seven or eight, a different 
picture emerges: almost half of the children at this age share with 
others and a clear majority shows a preference for the others' 
well-being. Importantly, this tends to be the case when dealing with 
one of their classmates.

The work forges an important link between being fair and looking 
after those who are from the same group.

"The simultaneous development of altruistic behaviour and preference 
of the own group provides interesting new impulses for the conjecture 
that both of these processes are driven by the same evolutionary 
process," says Prof Fehr, an economist at the University of Zurich.

However, he stresses that this does not mean parents should not 
encourage their children to share at an earlier age, since this 
"might be a decisive factor in the evolution of inequity aversion."

Dr Bettina Rockenbach, contrasts the difference with chimpanzees' 
behaviour. "Adult chimpanzees show no preference for sharing with an 
identifiable colleague.

"In contrast, almost half of the seven to eight year old children 
even share with an anonymous partner."