Originally posted by Aim64C
reply to post by melatonin
It's a problem of causality.
It is impossible, though any known method of observation, to determine whether or not our genetics can encode "mental images" that could be later
construed by our imaginations to be compiled into a sort of Chimera.
I'm not even speaking about such 'mental images' really. That perhaps suggests a more conscious awareness. I'm talking at the level of instinctual
responses, more fixed action patterns than something we might contemplate or have a 'mental image' of (although, as I take brain = mind, then we
could in some way agree).
For example, a few studies show that very young babies prefer to look at people viewed as attractive. Why? Why would they prefer an attractive face
cf. an unattractive face? Symmetry perhaps? Is this an innate preference? I doubt they learned it. A clear FAP in babies is the grasping response. If
I place an bitter/astringent substance in the mouth of a baby, they show a disgust response, is this instinct or pure learning?
An excellent example of an FAP is egg-rolling in the Greylag goose. When seeing a displaced egg it goes and retrieves it, rolling it back with its
beak. If you remove the egg after initiation of the behavioural pattern, it follows the behaviour through to completion with some imaginary egg.
This behaviour is initiated on exposure to the stimulus (egg) and the FAP is the response. Many other examples as well: e.g., sticklebacks - here
they can change the stimulus to see what base stimulus features trigger the FAP; predator response in naive fowl, species show flocking and mobbing
sensitive to different types of bird silhouette stimuli (some for shape, others speed, others direction). In the previous examples, we have stimulus
(predator odour) and response (stress and fear response, behavioural withdrawal).
These FAPs are more innate than learned. They are preprogrammed responses to highly salient and specific stimuli of different modes (olfactory,
visual, tactile etc). However, some predisposed behaviours do require a degree of fine-tuning and learning, and in many species, behavioural
flexibility is important (i.e. modification). Thus, FAPs can often be strengthened or weakened by experience (cf. reflex).
In the wider context of brain chemistry and behaviour. A good example is the lab studies on voles. Predictions can be made about the degree of
monogamous behaviour from the density of particular receptors (vasopressin for males; oxytocin in females). So here, the density of neural receptors
for certain chemicals determines the individual's promiscuity. By altering the neurochemistry, sexual behaviour can be altered.
The density of such receptors will be genetically determined to a large degree.
It "sounds" scientific, because it includes genetics and chemical reactions. But to use that as an explanation is not scientific. It's a
conjecture - and a faith-based conjecture, at that, seeing as there is no real way to verify the conjecture to be true or false.
Really what you are doubting here is the fact the genes can underpin and predispose to behaviour. I think you are very wrong, and the serotonin allele
studies in humans suggest this, along with the many other studies showing the relationship between genes and behaviour/psychopathology.
Genes do underpin the biological nature of brain, they predispose to emotional, cognitive, and behavioural drives. Of course, the brain is very
plastic, so we would ignore environment and learning at out peril. However, the idea of some Tabula Rasa is well abandoned.
[edit on 8-7-2008 by melatonin]