In considering the contribution of biological inheritance to behavioural choice[1], it is useful to first consider the case of organisms without neurological systems — the biological substrate of behavioural potential in metazoa (all animals except sponges). The biological potential — genome — of a plant is expressed as bodily structures with the potential to function interactively in specific ways. In terms of reacting to external stimuli, plants have sensors for detecting difference, such as the direction of light, and sequences of processes that follow from the detection, such as those that result in the re-orientation of leaves or the opening of flowers. Interactions with the outside world of perceivables are similar to those chain reactions that occur within the organism during its development and growth.
Similarly, the biological potential of animals, such as humans, is expressed as bodily structures (anatomy) with the potential to function interactively in specific ways (physiology). In terms of neurological systems, humans inherit (general) anatomical structures with their potential interactive functions, such as species-specific sensory abilities/activities, species-specific motor abilities/activities, and species-specific categorising abilities/activities of sensory and motor activities.[2] Note that this expression of biological potential cannot include “innate” categories of the perceivable world “hard-wired” into the brain, because this would require the inheritance of acquired characteristics (Lamarckism[3]), in as much as the categorising experience of previous generations would have to become coded into the genome of the species.[4]
While the ontogenesis of behavioural potential in the individual is a personal evolution which depends, inter alia, on experiencing domains that are outside the body, the categorisation processes involved are guided by value-imposing systems that are the phenotypic expressions of biological potential. These not only influence how behavioural potential adapts in the lifetime of the individual, but also affect the probabilities of behavioural choice in a given situation. This is because value-imposing systems link neurological activities to the homeostatic systems of the body, such that, in times of internal disequilibrium, such as hunger or fear, neurological events that immediately restore equilibrium states to the body are more likely to occur than those that don’t, ceteris paribus. The relationship between genes and specific behavioural choices, then, is probabilistic and contingently variable.
Footnotes:
[1] Bronowski, in The Ascent Of Man (ep1: 47:00), distinguishes cultural adaptation as those behaviours that can be changed from biological adaptation as those behaviours that cannot be changed.
[2] For neurological givens, see for example Sacks (1995: 105).
[3] Cf the Baldwin Effect. Dawkins (2004: 325):
Learning doesn’t imprint itself into genes. Instead, natural selection favours genetic propensities to learn certain things. After generations of such selection, evolved descendants learn so fast that the behaviour has become ‘instinctive’.
[4] While it can be said that types of somatic systems indicate to an observer what type of environment a lineage has adapted to, this is not the same as categories of the environment existing in the brain of the individual before beginning to experience that environment.