A leading anthropologist has questioned the popular idea that religion developed and spread because it encouraged social bonding, by arguing that faith and belief is nothing but a figment of human imagination.

Maurice Bloch of the London [Images] School of Economics argues that humans are the only species to practice religion because they are the sole creatures to have evolved imagination.

According to Bloch's theory, initially humans had to develop the essential brain architecture to imagine things and beings that don't subsist physically, and the likelihood that people somehow survive on after their death.

Once this was done, they had access to a form of social interaction unavailable to any other creatures on the planet.

Exclusively, humans could use what Bloch calls the 'transcendental social' to unite with groups, such as nations and clans, or even with imaginary groups such as the dead.

He explained that the transcendental social also permits humans to follow the idealised codes of conduct linked with religion.

'What the transcendental social requires is the ability to live very largely in the imagination,' New Scientist magazine quoted him, as saying.

'One can be a member of a transcendental group, or a nation, even though one never comes in contact with the other members of it. Moreover, the composition of such groups, whether they are clans or nations, may equally include the living and the dead,' he added.

He argues that no animals, not even our nearest relatives the chimpanzees, can do this. Instead, he says, they're restricted to the routine and Machiavellian social interactions of everyday life.

The reason for this, he says, is that they can't imagine beyond this immediate social circle, or backwards and forwards in time, in the same way that humans can.

Bloch believes our ancestors evolved the essential neural architecture to imagine before or around 40-50,000 years ago, at a time called the Upper Palaeological Revolution, the final sub-division of the Stone Age.

'The transcendental network can, with no problem, include the dead, ancestors and gods, as well as living role holders and members of essentialised groups,' he said.

'Ancestors and gods are compatible with living elders or members of nations because all are equally mysterious invisible, in other words transcendental,' he added.

But Bloch argues that religion is only one expression of this exceptional ability to form bonds with non-existent or distant people or value-systems.

'Religious-like phenomena in general are an inseparable part of a key adaptation unique to modern humans, and this is the capacity to imagine other worlds, an adaptation that I argue is the very foundation of the sociality of modern human society,' he said.

'Once we realise this omnipresence of the imaginary in the everyday, nothing special is left to explain concerning religion,' he added.

Bloch has detailed his findings in the journal of Philosophical Transactions of the Royal Society B.