Once language had pulled the various modules into communication, all sorts of fascinating interactions began between them. There were four modules, with six pairings, and each pairing had its own special consequence.
For example, the natural history module and the social relationships module interacted in a surprising fashion. The natural history module impelled humans to inquire into the causes of the phenomena that they observed in their environment, but all too often a clear cause was wanting. For example, an especially important question for the early farmers was, why did it rain? Or, more to the point, why did it sometimes fail to rain?
Once language put the natural history module in touch with other modules, it teamed up with the social relationships module to devise an answer that made some sense: natural phenomena were caused by powerful people: gods. Whenever a phenomenon lacked an obvious cause, it was a simple matter to assign the phenomenon to a god, then explain the apparently erratic behavior to the mood swings of the deity. Not only did the social relationships module suggest an explanation to the problem -- it also offered the solution: propitiate the god. A huge array of behaviors became associated with the various gods. Some acts were forbidden, others mandatory. And because the gods seemed so arbitrary, it behooved society to have somebody on hand who could communicate with the gods. There was never any shortage of applicants for the position; whoever communicated with the gods was, essentially, in charge of the society. There, now you know where religion came from.
But the natural history module was also able to interact with other modules, and when it interacted with the language module, it produced "sequential thinking natural history" -- science. It got off to a shaky start because sequential thinking took a long time to develop. But once the idea of syllogisms and chains of deduction took hold, science took off. The conflict between science and religion becomes clearer when viewed in this fashion. Both arose from the natural history module; both attempt to explain the world in which we live. Religion takes the social relationship route, where science takes the sequential logic route. One's choice between them may have more to do with relative strengths of these two modules than anything else.
But there are still four more interactions to consider. Two of them, I lump together: the combination of the visual/spatial module with both the natural history module and the social reasoning module to produce representational art.
When visual/spatial reasoning combined with the language module, we got writing, an impressive result. And when the language module combined with the social relationships module, it produced storytelling.
Here is a summary of the results:
For further information:
The Prehistory of the Mind by Steven Mithen