I'm really enjoying the book. Many thanks.
I want to suggest that the 'Baldwin Effect' is much more ubiquitous in nature than is generally acknowledged and I would welcome your thoughts.
As you point out yourself, spontaneous adaptive behaviour of individuals in a population will often be positively associated with genetically-mediated predispositions. This will result in an inter-generational positive feedback loop between the behaviour and the predispositions being created. Over time more and more individuals will manifest the behaviour together with the supporting dispositions. In effect, the behaviour gradually becomes part of the living environment that is 'selecting' alleles and so honing the architecture of the genome.
I consider it likely that this process was involved in all the adaptive behaviour we see in nature; spiders spinning webs, birds building nests, beavers constructing dams, etc. In our own species I suggest that language and religiosity, for example, started as spontaneous adaptive behaviours with positively associated predispositions; possibly intelligence/ curiosity.
John Jacob Lyons