(Press-News.org) People of differing competence tend to give each other's views equal weight, preventing them from making the best group decisions, finds new UCL-led research.
This suggests that people with similar levels of competence make the best decision-making groups, as otherwise the tendency to assume equal competence can give undue weight to the opinions of less capable members.
The new study, published in Proceedings of the National Academy of Sciences, investigated how pairs of people with differing competence weighted their own judgements against each other's.
Researchers split 98 men from Denmark, Iran and China into pairs and asked them to complete a visual perception task, repeated 256 times per pair. Participants were asked to look at a screen for two consecutive intervals, with a subtle target appearing in either the first or second interval. Each person, separated from the other by a screen, indicated whether they thought the target was in the first or second interval and how confident they were. When they disagreed on where the target was, one of the pair was randomly assigned as arbitrator and asked to make the final joint decision.
The results show that the more competent people - those whose first judgement was usually correct - tended to value their less competent partner's judgement more than they should have. Similarly, the less competent people valued their own judgements more than they should have.
On average, the more competent people were likely to be right approximately 70% of the time. As such, the logical choice when they disagreed with the less competent member would be to go with the other person's judgement 30% of the time. However, they actually went with their less competent partner's choice more than 40% of the time.
Similarly, the less competent people, who were on average 30% likely to get it right, failed to give due weight to their more competent partner's judgement. On average, they only went with their more competent partner's choice approximately 50% of the time.
People's tendency to act as though their partner was similarly competent, the 'equality bias', continued even when they were explicitly shown how well they were each performing throughout the tests. It also continued when the competence gap was artificially increased by secretly making the test harder for less competent members and when participants were offered money for correct decisions.
"People are incredibly bad at taking differences in competence into account when making group decisions," says senior author Dr Bahador Bahrami (UCL Institute of Cognitive Neuroscience). "Even when we showed them exactly how competent they each were, they still gave each other more or less equal say. Incredibly, this still continued when people were rewarded with real money for making correct decisions.
"The reasons behind equality bias are unclear, but one explanation could be that people are reluctant to take sole responsibility for group decisions. If people give others equal say in a decision then they share the responsibility for potential errors. Aversion to social exclusion may also play a part, as a less competent person may want their own decision represented so that they feel relevant and included. More competent members may want to avoid ignoring or excluding the other person."
The experiments were carried out across three different countries in order to test for any cultural biases, but there were no significant differences between the results. Equality bias therefore appears to be a universal human trait which could affect many different decision-making processes in modern life, from high-level policy decisions to everyday situations.
"For example, when people living together are deciding the best way to select utility suppliers and divide bills, they are likely to give each other's views equal weight," explains Dr Bahrami. "However, if one person is far more financially competent, then the best strategy for the group might be to give their judgement more weight."
INFORMATION:
This news release is available in German.
Reproduction at old age involves risks that may impact one's own life and may impose reduced biological fitness on the offspring. Such evidence, previously obtained in humans and other taxa under laboratory conditions, has now been confirmed by researchers from the Max Planck Institute for Ornithology in Seewiesen together with colleagues from the UK and New Zealand for the first time in free-living animals. In a long-term study on a population of house sparrows they found that offspring of older parents themselves produced ...
Nearly three out of four Chinese adults have poor cardiovascular health, with poor diet and growing rates of obesity compounding the risks associated with continuing high rates of smoking, according to a new survey published in the Journal of the American College of Cardiology.
The 2010 China Noncommunicable Disease Surveillance Group collected cardiovascular health data from a nationally representative sample of more than 96,000 men and women in the general Chinese population. According to estimates derived from the survey results, just 0.2 percent of Chinese men and ...
People in a society are bound together by a set of connections - a social network. Cooperation between people in the network is essential for societies to prosper, and the question of what drives the emergence and sustainability of cooperation is a fundamental one.
What we know about other people in a network informs how much we are willing to cooperate with them. By conducting a series of online experiments, researchers explored how two key areas of network knowledge effect cooperation in decision-making: what we know about the reputation and social connections of those ...
A new study suggests that increases in atmospheric CO2 could intensify extreme droughts in tropical and subtropical regions -- such as Australia, the southwest and central United States, and southern Amazonia -- at much a faster rate than previously anticipated, explains University of Texas at Austin professor Rong Fu in a commentary in the March 9 edition of Proceedings of the National Academy of Sciences.
Fu, a professor at the university's Jackson School of Geosciences, writes about a new study by William K.M. Lau of the University of Maryland and Kyu-Myong Kim of the ...
Once green, the Sahara expanded 5,500 years ago, leading ancient herders to follow the rain and grasslands south to eastern Africa. But about 2,000 years ago, their southward migration stalled out, stopped in its tracks, archaeologists presumed, by tsetse-infested bush and disease.
As the theory goes, the tiny tsetse fly altered the course of history, stopping the spread of domesticated animal herding with a bite that carries sleeping sickness and nagana, diseases often fatal for the herder and the herded.
Now, isotopic research on animal remains from a nearly 2,000-year-old ...
Despite extensive historical knowledge about the African slave trade - including trends in the volume and demographics of the roughly 12 million people shipped from West and West Central Africa to the New World between 1500 and 1850 - fundamental details about their ethnic and geographical origins remain elusive. Dr. Hannes Schroeder from the Centre for GeoGenetics at the Natural History Museum, University of Copenhagen, who led the study, explains:
- There are historical records - merchant ledgers, shipping records and the like - but they tend to refer to coastal shipping ...
In the ongoing Ebola outbreak in West Africa, whose death toll is approaching 10,000, little information has been available about how the human immune response unfolds after infection.
Researchers from Emory and the Centers for Disease Control and Prevention have now obtained a first look at the immune responses in four Ebola virus disease survivors who received care at Emory University Hospital in 2014, by closely examining their T cells and B cells during the acute phase of the disease. The findings reveal surprisingly high levels of immune activation, and have implications ...
March 9, 2015
PITTSBURGH--To fully understand how nanomaterials behave, one must also understand the atomic-scale deformation mechanisms that determine their structure and, therefore, their strength and function.
Researchers at the University of Pittsburgh, Drexel University, and Georgia Tech have engineered a new way to observe and study these mechanisms and, in doing so, have revealed an interesting phenomenon in a well-known material, tungsten. The group is the first to observe atomic-level deformation twinning in body-centered cubic (BCC) tungsten nanocrystals. ...
COLUMBUS, Ohio - Children whose parents think they're God's gift to the world do tend to outshine their peers - in narcissism.
In a study that aimed to find the origins of narcissism, researchers surveyed parents and their children four times over one-and-a-half years to see if they could identify which factors led children to have inflated views of themselves.
Results showed that parents who "overvalued" their children when the study began ended up with children who scored higher on tests of narcissism later on.
Overvalued children were described by their parents ...
A new study of Tourette syndrome (TS) led by researchers from UC San Francisco and Massachusetts General Hospital (MGH) has found that nearly 86 percent of patients who seek treatment for TS will be diagnosed with a second psychiatric disorder during their lifetimes, and that nearly 58 percent will receive two or more such diagnoses.
It has long been known that TS, which emerges in childhood and is characterized by troublesome motor and vocal tics, is often accompanied by other disorders, especially attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive ...
