Since I have started riding a bicycle to and from work on a fairly regular basis I have had a number of incidents allowing me to muse on my ancestors' contributions to my instincts.
Because I had a worse education than anyone I know, my understanding of this comes almost entirely from a book I read about ten years ago called How the Mind Works by an American called Steven Pinker; one of those pop science books by someone who is clearly groovy and who is also working a little outside their field of expertise but doing a better job of it probably for that very reason (I always teach better outside areas I am totally immersed in because apart from anything else I don't get bogged down in the detail). If I remember correctly Pinker claims in that book that the western cultural preference for a lawn with trees as a backdrop is innately satisfying to humans as evoking the daily existence of the prehistoric people of the savannah from which you and I and everyone else have evolved. The open space means we can see if anything is coming towards us to attack us; the trees mean if something does come towards us to attack us we have somewhere to run and hide. I may have got Pinker a bit wrong here but the gist is right.
If these ancient tropes are hard wired into us (don't you love those kinds of cliches; I have never heard the term 'hard wired' used any other way, is it really a process? In computers or what?) then I have another one. Numerous times, and it happened again this morning, I have had to fight the sense that I am riding into ambush. I know this sounds silly but it's a true sense. Riding on the bike path along Moonee Ponds Creek at Strathmore, for instance, one comes across a scenario of the creek to the right, and the major wall of the Tullamarine Freeway to the left. Here there is a wall of about waist height and then level ground of probably a metre across alongside the freeway wall. Here plants are growing with leaves and branches that hang off the wall toward the bike path. Most of the time at this time of year I approach these in the half-light, and my immediate response is to regard them as people standing by the pathway in a suspicious manner. The proportion is right - they look in an abstract sense to be people-sized - but the idea that people would stand at regular intervals along a fairly secluded bike path for any reason is absurd. Nevertheless I think you see what I'm saying. It's a primal impulse to be on guard against people-sized things in the distance, on your projected route, as they may actually be people.
This morning, the same thing happened again where I was only dimly aware of my intended course - I was travelling across the large park at the west of the Melbourne General Cemetery - and then somewhere in my ancient mind there was a distant alarm bell. I actually had to think about what the problem might be, and came to apreciate that it was an avenue of trees in the distance, with two people (walking away from me) in the middle of them. Allowing for perspective of the furthest trees, and comparison between the two people and those far trees, something in my head was telling me there was something that needed to be considered up ahead, potentially dangerous.
The really silly part of this is that, when for instance I'm driving and another driver does something wreckless or bizarre, I react calmly before I even think about it (most people are like this - it's a different kind of innate reaction, one that virtually bypasses the 'hmm, is that an avenue of trees or a death squad?' decision making process). So being prepared, while an advantage, is not the most commonly used advantage humans have. Also, if a group of people - unless it was those darned neanderthals maybe - wanted to ambush me, wouldn't they do it from some concealed position, rather than somewhere very conspicuous? I would have thought so, but maybe that's the trick.
That said, I do often think about that early scene in the film Children of Men where the burning car is pushed down the hill through the forest to the valley road to stop Julianne Moore getting away, or getting somewhere, I can't remember. That really pushed my buttons, which by the way, are directly connected to my hard wiring.