"Human evolution is usually depicted as driven by intelligence, with empathy and deeper emotions following," said Penny Spikins, who researches human origins at York University.
"However, the evidence suggests it happened the other way round. Evolution made us sociable, living in groups and looking after one another, even before we had language. Our success since then, including the evolution of intelligence, all sprang from that," Spikins said.
Spikins pointed to archeological finds hinting that even pre-humans had unsuspected emotional depths.
Australopithecines, our direct ancestors, were widely depicted as the 'killer ape' because skulls and bones in the cave had been smashed in what the 1930s archeologists who found them assumed was early warfare.
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But Spikins said australopithecines were hunted by other animals and survived by co-operating rather than fighting.
"What is remarkable is that this pebble was carried several miles back to its cave by an australopithecine. Did it remind them of a baby? It is impossible to tell for sure but this is not the only tantalising sign of something perhaps approaching tenderness," she said.
There is more evidence of empathetic behaviour in early humans. By 1.5m years ago, Homo ergaster was caring for the ill, while Homo heidelbergensis, which lived 450,000 years ago, appear to have nursed disabled children.
Spikins said early humans also had a sense of aesthetics.
This is suggested by a 250,000-year-old handaxe found at West Tofts in Norfolk, made from a rock containing a fossilised scallop shell and designed to make the fossil the centrepiece of the tool.