...and as Book Lover states above the assertion he is making is misleading. The presentation talks about "irrational" ideas being inherent in all humans. Of course many leaps in our knowledge and inventions as well were the result of "irrational" ideas.
The examples used to comfirm his theory relate experiments he posed where people were presented with an ugly sweater and he asked for a show of hands of those who wanted to wear it for £10. Only to see them draw back in horror once confronted with fact that the sweater was once worn by a killer (which it had not). Or the galvanic responses (lie detector science) of people when they are asked to cut up a photograph. Quite a leap to being "Hardwired For Religion," I'd say.
Do we have irrational ideas? Yes, maybe so. But the relationship that this theory has to the development of religious beliefs are neither confirmed nor denied from the examples used. As you point out in your examples about early humanity, religion "developed" in response to our need for things to make sense. For them to be explained in some way. If these responses are located in specific parts of the brain, that would be little different than other "responses, drives and inherited traits" of other kinds of human respones which have developed over the generations. IMO
One study you might be referring to about there being no specific location or "God Spot" in the brain:
Brain Scan of Nuns Finds No Single God Spot In the BrainA new study at the Université de Montréal has concluded that there is no single God spot in the brain. In other words, mystical experiences are mediated by several brain regions and systems normally implicated in a variety of functions (self-consciousness, emotion, body representation). The study published in the current issue of Neuroscience Letters was conducted by Dr. Mario Beauregard from the Department of Psychology at the Université de Montréal and his student Vincent Paquette.
"The main goal of the study was to identify the neural correlates of a mystical experience," explained Beauregard. "This does not diminish the meaning and value of such an experience, and neither does it confirm or disconfirm the existence of God."
Fifteen cloistered Carmelite nuns ranging from 23 to 64-years-old were subjected to an MRI brain scan while asked to relive a mystical experience rather than actually try to achieve one. "I was obliged to do it this way seeing as the nuns are unable to call upon God at will," said Beauregard. This method was justified seeing as previous studies with actors asked to enter a particular emotional state activated the same brain regions as people actually living those emotions.
This study demonstrated that a dozen different regions of the brain are activated during a mystical experience. This type of research became very popular in the United States in the late 1990s. Some researchers went as far as suggesting the possibility of a specific brain region designed for communication with God. This latest research discredits such theories.
http://www.scienceblog.com/cms/brain-scan-of-nuns-finds-no-single-god-spot-in-the-brain-11388.html