Morality Under a Microscope: Moral Actions and Their Impact on the Brain

Introduction

From philosophers to psychologists, curious minds have long sought to understand what biologically motivates humans to operate within a system of morality. At its core, morality is a set of principles that distinguish between right and wrong [1]. For example, stealing candy from a baby is generally considered morally wrong, whereas donating money to a homeless person is considered morally right [2]. 

Neurologically, the understanding of morality is largely attributed to how the human brain reacts to moral choices– specifically, how these choices trigger the release of neurochemicals that produce either pleasant or unpleasant feelings [3]. The constantly shifting expression of morality and its lasting impact on human history makes it important to understand how human minds construct notions of right and wrong [4]. Although research on the human mind may be considered ethically controversial–and at times dangerous– it is morality’s continued significance in human history that underscores the necessity of this research [4]. By exploring these complexities, a path is paved for self-actualization and further progression as a species.

Morality and The Brain

The brain is a notably complex organ that stimulates physical, mental, or emotional functions through neural activity. One of the brain’s most significant functions in humans is critical thinking and decision-making abilities fundamental to making moral judgements [5]. 

While cultural upbringing affects how the brain interprets and implements moral decisions, the stimulation of specific regions of the brain has shown consistency across individuals. Specifically, the ventromedial prefrontal lobe (VMPC) displays increased activity when individuals confront a moral dilemma [6]. This region of the brain sends signals to the brainstem, causing the body to respond to sensory stimuli and neurobiological chemicals, such as dopamine, that are linked to moments of pleasure or gratification. 

The VMPC sits in the frontal lobe region, where emotions, motor skills, and critical thinking originate [7]. Some researchers argue that the VMPC is crucial to the essence of an individual–from beliefs to behavior. Damage to this region can potentially change a person fundamentally, as supported by a 2007 study linking VMPC damage to deficits in social emotions [6].

A History of Morality

Evidence of a primitive form of moral behavior dates back nearly six million years ago and was observed in chimpanzees, our evolutionary relatives. While they hunted and gathered in groups, individual chimpanzees would often hoard food, prioritizing self-preservation over collective good. In contrast, the Homo heidelbergensis, a direct human ancestor, implemented new survival methods based on collaboration which helped the species as a whole. This shift led to practices such as collaborative foraging, resource sharing, communal sheltering – a “we before me” mentality that laid the foundation for human evolution [8]. 

With communal living came the necessity for structure, and as human societies formed, so did culture [2]. Morality evolved as a tool to enhance the shared way of life and guide the younger generations towards behaviors that promoted group survival [8]. Hence, what humanity views as the “moral compass” is actually a unique part of the human consciousness which ensured the survival and development of the Homo sapien species [2]. 

Research Throughout the Years

Early philosophical figures such as Plato, Kant, and Hume deeply studied and debated the nature of morality. These debates typically involved two schools of thought: Utilitarianism (consequence matters most) and Deontology (intention matters most) [9]. Before modern scientific methods were used to study the brain, these early debates helped plant the seeds for ongoing research into how humans experience morality and how it connects to the brain.

Research into morality, in more than 1,000 empirical studies ranging from the 1940s to the 2010s, oscillated in focus between observed moral judgements, social development, and cultural norms [5]. It was not until the dawn of the 21st century that neurobiology began to be heavily integrated into the conversation on moral expression.

For example, Dr. Liane Young began her research by focusing on patients with lesions on the VMPC. After witnessing a correlation in emotion and moral judgement, Dr. Young continued to observe brains in relation to moral hypotheticals. She found brain regions like the right temporoparietal junction (rTPJ) were actively involved when individuals evaluated the intentions behind others' actions. Using functional magnetic resonance imaging (fMRI), her team found increased rTPJ activity when participants considered scenarios involving attempted harm without actual negative outcomes [2]. Modern neuroscience benefits from such research in many ways, ranging from understanding emotional reasoning post brain trauma to validating fMRI in clinical use.

Future Directions

While morality research has been ongoing for centuries, many questions on the neural underpinnings of morality remain unanswered. There is no set region of the brain that operates to control morality, as multiple brain circuits are found to work in conjunction [7]. Not to mention, all of this research has been conducted in regards to moral reasoning, whereas moral behavior has largely been neglected [5]. These studies focused on beliefs of right or wrong, but not how it changed behavior. As a result, much of the discussion on morality remains abstract. 

The need for more concrete research on moral behavior is clear, but scientific research involving humans has had a track record of being unethical. Since morality is tied to a very sensitive part of the brain, it is easy to see why many find this kind of research unsettling. However, the history behind moral choices and their importance on singular individual expression reveals an inherent desire for humans to learn more about morality. And, in doing so, the potential exists for great strides in brain damage rehabilitation. After all, the neurons which compose moral reasoning in the brain also inform a person’s essential character. Working to understand morality is, in effect, a work to understand the brain. As people suffer from brain damage and their families lose the essence of the person they once knew, continued research on morality has the potential to improve and perhaps even restore what has been lost in the brain.

References

1. Gert, J., & Gert, B. (2025). The definition of morality, Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/ENTRIES/morality-definition/  

2. Palmer, C. (2021). The Science of Morality. Apa.org; American Psychological Association. https://www.apa.org/monitor/2021/06/lab-science-morality

3. Schultz W. (2016). Dopamine reward prediction error coding. Dialogues in clinical neuroscience, 18(1), 23–32. https://doi.org/10.31887/DCNS.2016.18.1/wschultz

4. Miller, G. (n.d.). The roots of morality - NYU. SCIENCE. https://people.stern.nyu.edu/jhaidt/articles/miller.2008.roots-of-morality.science.pdf 

5. Ellemers, N., van der Toorn, J., Paunov, Y., & van Leeuwen, T. (2019). The Psychology of Morality: A Review and Analysis of Empirical Studies Published From 1940 Through 2017. Personality and Social Psychology Review, 23(4), 332–366. https://doi.org/10.1177/1088868318811759

6. Koenigs, M., Young, L., Adolphs, R., Tranel, D., Cushman, F., Hauser, M., & Damasio, A. (2007). Damage to the prefrontal cortex increases utilitarian moral judgements. Nature, 446(7138), 908–911. https://doi.org/10.1038/nature05631

7. Pascual, L., Rodrigues, P., & Gallardo-Pujol, D. (2013). How does morality work in the brain? A functional and structural perspective of moral behavior. Frontiers in integrative neuroscience, 7, 65. https://doi.org/10.3389/fnint.2013.00065

8. Tomasello, M. (2024). The origins of human morality. Scientific American. https://www.scientificamerican.com/article/the-origins-of-human-morality/ 

9. Körner, A., & Deutsch, R. (2022). Deontology and Utilitarianism in Real Life: A Set of Moral Dilemmas Based on Historic Events. Personality and Social Psychology Bulletin, 49(10), 1511-1528. https://doi.org/10.1177/01461672221103058