Emotion vs. Reason: The Neurobiological Architecture of Human Nature

“The intuitive mind is a sacred gift and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift.”  

Albert Einstein

The question of human nature is central to the fate of humanity. Are we selfish or altruistic? Competitive or cooperative? Do we have a sense of personal responsibility and free will or are we mere marionettes who respond to external stimuli? Are we rational calculative machines designed to maximize economic utility or are we passionate spontaneous creatures full of compassion and care for each other?

The answer to these questions depends on various cultural and contextual factors. It is rather the question of whether it was the chicken or the egg that came first. No-one doubts that our culture shapes human nature. But it is highly likely as well that our dominant culture reflects our deepest intimate beliefs about “Who we are?” and “What is our purpose in life?” We design our public and social institutions, we promote social norms and practices based on how we view ourselves and each other — do we believe in the bright or dark side of human nature?

If you start searching for answers to these existential questions, you will become overwhelmed by all these philosophical speculations and never-ending reflections about the virtues and vices of humans. The debates have been lasting for centuries and have never been fruitful, no overarching consensus about human nature exists to the date. The situation has started to change recently, however, with the advent of new advances in cognitive neurosciences and moral psychology.

The study of neurological patients with abnormal human and social behavior has shed some light on the crucial aspects of human cognition that distinguish healthy humans from brain-damaged individuals. In fact, the extreme cases of human condition — outliers — has helped researchers to illuminate the true nature of human beings and what are the deviations from it. These unexpected breathtaking discoveries challenge and prompt us to revisit our taken-for-granted assumptions about ourselves and fellow human beings.

The role of emotion in real-life decision-making

In Western intellectual thought and traditions based on Cartesian split between mind and body, emotion has been often disregarded or seen as something undesirable in the process of a rational decision-making. What a surprise was to discover that individuals with emotional impairment — who have undergone damage to their emotion-processing brain regions and thus has lost their physiological reactions to emotionally charged situations, pictures or words — demonstrate striking deficits in their decision making and behavior in real life situations under conditions of uncertainty and ambiguity.

A growing body of clinical evidence suggests that these emotionally impaired individuals systematically demonstrate:

  • insensitivity to future consequences of their decisions and actions: they become unable to make advantageous long-term choices;
  • dissociation between knowing and doing: while knowing what is good vs. bad behavior, they are unable to act upon this knowledge;
  • lack of willpower and self-discipline: they exhibit impulsive behavior and develop various addictions (drugs, money, food, etc.)
  • utilitarian thinking: without emotion-laden knowledge and experiences, such individuals heavily rely on “cold-blooded” cost-benefit analysis (i.e., a pure economic rationality);
  • unethical or inappropriate social behavior: without guilt and remorse, they do not care about others and focus solely on their own self-interest.

Neurobiological basis for a healthy human cognition 

To understand what is wrong with these unfortunate people and how a healthy human cognition operates, it is important to dig deeper into the evolutionary structure of human brain and appreciate the critical self-regulating role of human emotion. As we discussed elsewhere, emotion gradually evolved from simple pain vs. pleasure sensations in the reptilian brain and basic emotions of the mammalian brain towards more complex feelings and emotions to support a higher-order cognition in the human neocortex.

There are two interrelated emotion-processing brain regions essential for a healthy decision making and behavior under conditions of uncertainty:

  • Amygdala — is the seat of basic emotions or innate dispositional representations such as fear, anger, joy or grief. These automatic, rapid emotional signals are triggered in response to various external stimuli, objects or social situations to inform about immediate outcomes (pain vs. pleasure, reward vs. punishment). The amygdala assigns a certain emotional value to environmental stimuli in order to learn the goodness and badness of objects, behaviors and actions.
  • VMPFC (ventromedial prefrontal cortex) is a higher-order reflective system responsible for the integration of affective and cognitive information. Known as “the thinking part of the emotional brain” (1), VMPFC accumulates and consolidates emotional input from amygdala so as to generate more complex secondary emotions or intuition. These acquired dispositional representations manifest themselves as “gut feelings” and “embody knowledge pertaining to how certain types of situations usually have been paired with certain emotional responses, in your individual experience” (2).

Therefore, basic emotions generated by amygdala are associated with affective value of immediate outcomes while complex emotions or intuition, generalized from a person’s learning and life experience, are critical to assess the significance of long-term consequences of individual decisions and actions. During the process of decision-making, “the immediate and future prospects of an option may trigger numerous affective responses that conflict with each other; the end result is that an overall positive or negative signal emerges” (3).

Indeed, if an individual possesses an emotionally salient past experience related to an external stimuli then VMPFC responses will dominate, but if socio-emotional learning is lacking or the access to this emotion-laden knowledge is lost — like after a brain lesion — then impulsive responses associated with an immediate reward will win out. For this reason, the VMPFC dysfunction “leads to loss of self-directed behavior in favor of more automatic sensory-driven behavior” manifested by impulsive behaviors and various forms of addiction (4).

The functions of the chief executive of the emotional brain

The reflective VMPFC system exerts the top-down control over automatic emotional responses and even decides whether or not to integrate emotion into cognition by “computing the contextual relevance of emotional information for decision making” (5). Without this critical executive function, the “rationality that makes us distinctively human and allows us to decide in consonance with a sense of personal future, social convention, and moral principle” becomes severely compromised (6).

Neuroimaging studies demonstrate that the VMPFC:

  • is a key neural substrate for “envisioning emotional events in the far future” or generating “mental representations of future events that pertain to long-term goals” (7);
  • plays a critical role in value-based decision-making processes by computing “expected value, reward outcome and experienced pleasure for different stimuli on a common value scale” and then transforming value signals into a specific choice or action (8; 9);
  • is a part of “the neural circuitry that is causally involved in normative, fairness-related decisions” so that when fairness and economic self-interest are in conflict healthy individuals are able to choose the costly normative option (10);
  • is a critical part of neural circuitry responsible for exercising self-control and self-regulation in a goal-directed decision making (11; 12);
  • is a part of neural network for processing of moral and aesthetic beauty (13, 14);
  • is indispensable for moral development and behavior (15; 16);
  • has “a unique role in integrating cognition and affect to produce the empathic response” (17);
  • is important for creativity as the grey matter volume (GMV) in this brain region is positively associated with cognitive flexibility and assessment of individual creativity (18; 19);
  • plays a key role in self-regulation and stress resilience (20);
  • may underlie the human capacity for complex social interactions and abstract-state-based decision making (21);
  • may play a key role in the construction and modification of self-representations — “Who we are?” and “What is our personal significance?”(22).

Nonconscious intuitive mind as the seat of human nature

This evidence from neurosciences suggests that human ability for a higher-order cognition (i.e., long-term planning, self-control, morality and creativity) resides in higher-order nonconscious brain regions responsible for emotional processing. This nonconscious emotional brain embodies the tacit knowledge that humans continuously learn from their personal and social experiences. Individuals — through interactions with their social environment, through pleasant and unpleasant personal experience or reward/punishment mechanism — implicitly make associations between different types of stimuli (persons, situations, behaviors) and their own emotional or somatic (bodily) states.

As personal and social experience accumulate, human minds develop the ability to “generate estimates of probabilities” for anticipating “a certain degree of badness or goodness” for future outcomes of their decisions and actions (23). This nonconscious emotion-laden knowledge mediates decision-making process covertly “by enhancing attention and working memory related to options for action and future consequences of choices, as well as to bias the process overtly, by qualifying options for actions or outcomes of actions in emotional terms” (24). By imbuing “behavioral options with affective significance” (25) our intuitive mind helps us to choose advantageously among different, often conflicting options for actions and act in accordance with our values and long-term goals.

What is the role for conscious rational mind?

The nonconscious emotional or intuitive mind is the default cognitive process, handling everyday decisions and actions “in a rapid, easy, and holistic way” (26). It is used in real-time situations under conditions of uncertainty and ambiguity when individuals don’t have time for deliberate thinking (27), when their cognitive resources are limited (e.g., cognitive load, lack of sleep) or there are no external cues or salient social norms for guiding individuals’ choice and behavior (28).

By contrast, conscious rational thinking is an effortful cognitive mechanism that requires time and energy. It is associated with an activation of dorsolateral prefrontal cortex (DLPFC) responsible for cognitive control (29; 30). Since this intentional cognitive mechanism is time-consuming and energy-intensive, it is used for specific ends such as:

  • justifying our own decisions and actions or for influencing other people’s minds — scholars argue that “deliberate rational reasoning is often post hoc rationalization for judgments which have already occurred” in our subconscious mind (31);
  • calculative cost-benefit analysis— while healthy individuals use their analytic thinking only after the most harmful options for action have been eliminated by their rapid intuitive mind, VMPFC-damaged individuals use uniquely the DLPFC in their (utilitarian) decision-making;
  • adjustment of our automatic emotional responses for a specific context — value signals encoded in the VMPFC can be modified or even suppressed by the DLPFC if they are not adequate for a given situation. For example, individuals with prosocial values may reduce their spontaneous helping & cooperative behavior after some reflection but the opposite is true as well when proselfs refrain from their opportunistic selfish behavior if the risk of punishment is high.
  • resolving conflicting motives or value inconsistencies. As O’Reilly put it: “If a given action is associated with high levels of conflict or error, then more cognitive effort will be required, or it will not be as likely to be taken” (32). Studies show that the functional connectivity or interplay between intuitive effortless mind (VMPFC) and slow cognitive control (DLPFC) help individuals to reconcile often contradictory values (e.g., taste vs. health in food choice or self-interest vs. fairness in interpersonal behavior) so that they can exercise self-control and make an advantageous long-term choice (33).

Implications for Human Nature

So what this evidence from neuroscience teaches us about human nature? The good news is that the neurobiological machinery of human brains is well-equipped or at least designed well enough to learn and apply complex social knowledge and ethical rules for interpersonal interactions — that give rise to uniquely human higher-order cognition (e.g., long-term planning, morality and creativity). Our nonconscious emotion-processing brain headed by the VMPFC is in charge for our healthy human development and functioning.

The bad news is that our brains are also highly malleable and context-specific. That is, the same emotion-processing mechanism responsible for our humanity might be subject to adverse external influence (e.g., business education) and can be used for Machiavellian anti-social goals and behaviors. A neuroimaging study involving university students playing economic games found out that while healthy individuals have an emotional bias toward cooperation — that can be suppressed with effortful cognitive control, highly psychopathic individuals have an opposing emotional bias toward defection — that they can override with cognitive effort (in DLPFC) when they “opt for a morally appropriate action” (34). This evidence suggests that any kind of social information or “subjective beliefs” can be encoded in the nonconscious emotional brain based on the frequency of exposure to different kinds of stimuli (35).

The power of context or social norms is not only critical during human brain maturation— the “window of opportunity” lasts till the age of 23–25 years old — but also during the process of decision-making. In fact, our prepotent emotional tendencies can be overridden by cognitive control to comply with social expectations of the current context. An important study surveying executives of large corporations reveals that, despite their personal ethics, directors believe that their legal duty is to maximize shareholder wealth at the expense of social or ecological concerns. As a result, they are willing to “cut down a mature forest or release a dangerous, unregulated toxin into the environment in order to increase profits” (36).

Humans can be good or evil, smart or dumb depending on cultural factors such as education and social norms. In fact, we can be molded as one wishes. If we’d like to unleash our true human potential as moral and intelligent beings, we have to reshape our cultural environment —  we have to revisit our deepest beliefs about human nature in light of recent advances in cognitive neurosciences. As one cognitive scholar eloquently put it, “Changing the world is a very powerful way of changing behavior; changing the individual while leaving the world alone is a dubious proposition” (37).

Related posts:

Why Beauty will Save the World: A Brain-Culture Interaction
The Triune Brain: Evolutionary Foundations for Human Goodness
Why do Economists behave badly...like Psychopaths?

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