Why Do We Do One Thing and Say Another?
Throughout history, our behaviour has been dominated by an innate drive for survival. Often our strongest desires are also the ones that are the oldest evolutionarily; the congenital impulses that will aid our ability to reproduce and pass on our genes to the next generation. Over time, the brain has developed and evolved to enable more sophisticated behaviour. Around 500 million years ago, a genetic mutation resulting in an entire genome duplicating on two occasions paved the way for the evolution of advanced, complex brains. This serendipitous phenomenon facilitated the existence of numerous ‘spare’ genes, capable of evolving in many different directions to enable the expression of multiple neurotransmitters. As a result an autocatalytic cycle was created; enabling repeated innovation of thought and behaviour.
One critical development in the evolution of the human brain has been the formation of executive function. Amongst other processes, this system is responsible for reasoning, problem solving and planning, eliciting the cognitive control of behaviour. This includes the ability to select, monitor and attain goals, and is subsequently crucially important in the maintenance of sustained, effortful behaviour, such as losing weight or quitting smoking.
This interaction of executive function with other systems is conceptualised in Dual-Processing theory, which elaborates upon the presence of two decision-making systems in the brain – the ‘hot’ and the ‘cold’. The cold system refers to a more rational, cognitive and evolutionarily younger system responsible for thoughtful, measured decisions. In contrast, the ‘hot’ system commands impulsive, emotional and fast selections.
An essential aspect of this interaction is the ability of the hot system to override the cold, meaning long-term goals can often become interrupted by immediate gratification. This can be attributed to two causes; the relative evolutionary maturity of the hot system, and the resource dependency of the cold. Whilst the hot system is able to function consistently over time, providing it does not receive structural damage, the cold system must be provisioned with sufficient resources in order to perform. Consequently, if an individual is tired or hungry, their cognitive resources may be considered depleted, and their decision-making and self-control compromised.
Therefore the parallel functioning of both our instinctive drives and cognitive operations explains a great deal about our capabilities in decision-making. Whilst both systems often work in collaboration, the desires of each system do not always necessarily align. As a result, the ability to reach our cognitive, long-term goals can be disrupted by instinctive emotional impulses, especially if we are cognitively depleted. The ‘Value-Action’ gap describes the inconsistency between our intentions and actual behaviour; often we intend to carry out one action and in reality conduct another. For example, an individual may commit to reducing their sugar intake whilst in a rational frame of mind, however cravings for chemically rewarding foods can become an overpowering enemy in the battle to loose weight, once cognitive abilities becomes impaired by hunger.
Importantly, the interaction between the two systems of decision-making happen outside of conscious thought, leading us to assume the illusion of rational control over our own decision-making, when often this is not the case. Frequently our actions result from hot, emotional, impulses, masked by a veil of apparent rationality; we make an instinctive decision, and then later justify it according to rational constraints. This compounds the problem of the value-action gap; it is even harder to commit to focused, goal-driven behaviour if we can subsequently justify deviations from this behaviour to ourselves.
The importance of the dual-processing system and the sometimes-irrational decisions that result from this structure, it is found in their application to research and policy. The evidence supporting the existence of different and sometimes confounding decision-making systems is clear; the next question, is how do we use them?