A new study has it that two heads are better than one, but only when your partner is competent and communicative.
Chris Frith of the Wellcome Trust Centre for Neuroimaging at UCL (University College London) and Niels Bohr, Professor in the University of Aarhus, conducted the study to find if two people can combine their individual sensory information to arrive at a judgment that is more accurate than from either source on its own.
"For our study, we wanted to see if two people could combine information from each other in a difficult judgment task and how much this would improve their performance," said Dr Bahador Bahrami, lead author of the study from UCL.
The results showed that if the partners were willing to talk to each other and arrive at a mutually agreeable decision, the joint decisions were better than any one person's judgment.
But the results were not optimal when one partner was either incompetent or unwilling to discuss.
"When one person is working with flawed information - or perhaps is less able at their job - then this can have a very negative effect on the outcome. Being able to work together successfully requires that we know how competent we are. Joint decisions don't work when a member of the team is incompetent, but doesn't know it," Frith said.
"We know all too well about the catastrophic consequences of consulting 'evidence' of unknown reliability on problems as diverse as the existence of weapons of mass destruction and the possibility of risk free investments," he added.
The study is published today in the journal Science.