The Myth of the Enduring Personality - Part V

Part I of the series here

Neurotransmitters

At this point, a trait theory might like to invoke the concept of neurotransmitters. Implicit in trait theory is the need to point to neurotransmitters as being the cause of behaviour. It may seem so far that I have ignored the idea of neurotransmitters being influential in this process, and am dismissing their importance. 

It may be the case that since physical and mental states are one and the same thing, John's new way of thinking after CBT is a result of a change in the balance of neurotransmitters. 

We could argue about the plasticity of the brain and how it adapts over time, and this relates to the experiential component we described previously. Going back to John's condition, a trait theorist could bite the bullet and suggest that being shy is an experiential disposition, or 'trait of character' as Fisher writes. 

John was only affected by anxiety in the presence of strangers, and a trait theorist could claim that this is a purely experiential component. If we were able to establish a link between neurotransmitters and behaviour this would support this line of argumentation.

Implicit to such a counter-argument is that we will act the same way in similar situations because we have enduring traits. To account for any deviation from this we have to appeal to dimensionality and allow that neurotransmitters influence our behaviour along a dimensional axis. 

However, this leaves little room for manoeuvre when we consider that we may have major life events that cause our behaviour to change drastically from the traits we are ascribed. A death or traumatic event in the family may cause our behaviour to deviate from these fluctuations in dimensionality. 

This might mean we are enveloped in a terrible sense of melancholy that is somewhat out of character and is of a temporal duration. It is pushing the bounds of trait theory too far if we were to suggest that new traits appear, or we swing to extremes on fixed dimensional planes. 

This account would be missing out on the kind of volatile mood swings, memories, and projections that would feedback into our psychological world during a traumatic time. A functionalist account might be better placed to capture this aspect because it would not rely solely on neurotransmitters*. It allows causal interactions between our mental and physical states, however, trait theory is not afforded this luxury, since its aim is to explain psychological differences in purely physical terms.

* Footnote: A more advanced trait theory might like to try and exploit this functionalist view, however, this would be untenable for reasons we will outline shortly. Essentially, this boils down to the fact that we cannot clearly delineate between traits and our own personal view point. We will treat this matter fully in due course.

Perhaps more damaging to trait theory is the whole edifice of this argument stands or falls on the assumption that neurotransmitters are the cause of our behaviours. Butt pointed out that neurotransmitters may be sufficient but not necessary to cause behaviours, and the simplistic notion of neurotransmitter changes driving behaviour has no empirical support (Butt, 2004). 

Despite all the appeals to neurotransmitters, it has never been established in any studies that they are the causal mechanism for our behaviour. 

Certain behaviours may be correlated with changes in neurotransmitters, however, this alone is insufficient for any explanation of behaviour. For instance, testosterone may be said to make us more aggressive and research has shown that playing sports produces high levels of testosterone. However, this does not necessarily mean aggressive behaviour and violence will result, although we can observe there is a correlation (cited in Butt, 2004). 

This suggests that dimensionality cannot be explained in terms of neurotransmitters alone, and consequently we are unable to account for the complexities of human behaviour by merely appealing to neurotransmitters pushing us back and forth along a categorised dimension.

A New Approach to Traits

Assigning traits and categorisations is a natural propensity to social beings like us. These descriptions are useful in our day to day lives and interpersonal relationships. However, once the light of reality is allowed to illuminate the landscape, we find nothing tangible and no solid basis for grounding traits. In this orthodox trait theory we have found that there are no grounds to assert that neurotransmitters are a necessary cause of behaviours. 

We need not deny there is any correlation or that they play a role, but it is certainly asking far too much to suppose that neurotransmitters can fully account for the dimensionality of our behaviour. 

Furthermore, such an account has no coherent justification for explaining how extremes of uncharacteristic behaviour occur in traumatic circumstances. We can go from the pits of despair to elation in an instant, and we can ask for an account of how neurotransmitters can fluctuate so much so as to cause this, particularly when we are trying to make sense of behaviour in terms of traits? 

Clearly, we are giving an impoverished account by pointing merely to fixed traits. As we have seen there is little basis for them, nor is there any evidence to suggest any enduring mechanism is responsible for them.

So, given that there clearly are patterns in peoples behaviour, does it not make sense to try and categorise them? 

Yes, it does make sense and we use these terms when describing people, however, we are now left with the question of where do these categorisations originate from, if not from psychological and biological dispositions? 

It is one thing to deny the existence of these traits, yet we must be able to convincingly account for why the notion of traits is so widespread. So, where does this illusion come from?

Part VI here...