On the quiescence of travelling toddlers

My grandchild often gets me thinking. Today, for instance, she woke up early, full of beans and a constant source of activity and attention. And we decided to take her into town. We decided to walk in and that she would therefore be in her pushchair (it did seem to us that asking her to walk 2 miles was a bit much for a 3 year-old). But then the everyday 'miracle' occurs, as it does so often and with so many toddlers: she was quiet and simply sat there for the walk down, for the walk around town in various shops and the walk back. Ne'ery an attempt towards active play. It was like she'd reached an altered state of consciousness.

And, on reflection, that's what I suspect it was: a quasi-trance state. Then my further question occurs: how come? Why is it that toddlers and babies tend to go quiet when travelling in these sorts of ways? Well, to me an evolutionary psychological hypothesis seems plausible. The children (and their parents, probably) who survived predation on the savannah would be the ones who stayed quiet when travelling. Then that begs the question: how would kids who cannot yet consistently form the kind of complex concepts we often express as 'if ... then ...' based on an abstract conditional ('if I make a noise /remain quiet') and a hard-to-conceptualise consequent ('we will/not attract the attentions of leopards') know to stay quiet and still? This is a question about what would cue them, presumably at something like an instinctual level. I would hypothesise that the rhythm (of walking or similar) and sight of of moving scenery cues/primes a transformation of consciousness to one that doesn't' need entertaining and is able to damp down the felt need for food or 'grooming'/interaction.

If this were so, then a further question-complex arises: does this instinct survive childhood, and if so, how does it show itself? This is even more speculative, of course, but I'm going to hazard a -hopefully- educated guess.

When I go for a walk I tend to find that my state of mind is not quite the same as 'normal'. In fact I often find that going for a walk enables my mind to produce ideas and solutions to problems that I've not achieved with conscious and focused attention to them in an office or meeting. So is this the same or a derived state of mind to that I think that our toddler grandchild seems to go into when in her pushchair? And if it is is it a good state for more discursive and creative way of thinking? Does it help meditative practice? (Seems to).