Some 2,500 years ago, legend has it, visitors to the Oracle at Delphi in Ancient Greece had to pass by an inscription bearing the words gnothi seauton — know thyself.

That advice is as wise today as it was then — and as hard to follow. Modern science can help, but using it to uncover truths about ourselves can also be fraught with difficulty. Consider, for example, that an important first step towards understanding contemporary human behaviour — establishing the evolutionary context in which it emerged — means piecing together odd scraps of evidence left by our hunter-gatherer ancestors tens of thousands of years ago. The paucity of data makes it all too easy to come up with untested, and even untestable, Darwinian versions of Rudyard Kipling's Just So Stories.

Now is a particularly opportune moment for those studying human behaviour to share their data.

Another major challenge for researchers is being objective about a topic as philosophically, politically and ethically charged as human nature. Take the sociobiology wars of the 1970s and 1980s. Left-wing scholars rejected biological explanations for phenomena such as gender roles, religion, homosexuality and xenophobia, largely because they feared such explanations would be used to justify a continuation of existing inequalities on genetic grounds. The resulting debates became hugely political.

The combustibility of the interface between science and society is one major reason for the extraordinary fragmentation of research that tackles human behaviour. In part because of the sociobiology battle, most social scientists still steer clear of using evolutionary hypotheses. And even researchers who do work under the unifying framework of evolution tend to fall into distinct camps such as gene–culture co-evolution or human behavioural ecology — their practitioners divided by differences of opinion on, say, the relative importance of culture versus genes.

Given that humans are such a complicated species, it is no surprise that researchers from fields such as economics, political science, anthropology and biology are driven to pursue similar questions using their own distinct tools and approaches. But the lack of crosstalk between disciplines and subdisciplines means that efforts are too often duplicated, and opportunities to exchange insights lost. Much of the ethnographic data on hunter-gatherers collected by anthropologists, for instance, are largely unknown to modellers interested in the emergence of particular human traits. Similarly, evolutionary biologists constantly accuse social scientists of either ignoring evolution or invoking outdated versions of evolutionary theory.

It doesn't have to be this way. In other domains, such as the study of complex systems, scientists from biological, physical and social sciences are increasingly sharing information. Now is a particularly opportune moment for those studying human behaviour to follow suit. Genomics is beginning to provide a window onto many thousands of years of human history. Advances in mathematical analyses have greatly clarified our picture of the evolutionary process. And, because of the rapid assimilation of nomadic hunter-gatherer populations into modern societies, researchers have collected most of the ethnographic data on these groups they are ever likely to obtain.

In the spirit of fostering dialogue between disparate fields of research, Nature has commissioned a series of Essays that asks how discoveries in psychology, anthropology, genetics, neuroscience, game theory and network engineering are altering our understanding of particular human characteristics, or of issues that are central to human life. Starting this week with religion (see page 1038), and appearing every two weeks for the next five months, these Essays move from human prehistory to look at how we operate within self-made highly interconnected cities and communication networks.

Cumulatively, the series indicates that the interface between science and society is no less thorny now than it's ever been; revelations about our appetite for warfare in an Essay on conflict, for example, will make for uncomfortable reading. But overall, practitioners from diverse areas of research deliver an optimistic message about how we may learn to manage ourselves more effectively as a result of knowing ourselves better.