The Taste of Immorality in the Brain

Immorality is inevitably tied to social constructions and our value system. Ultimately, it is defined by the idea of morality inherent to our social context. We seldom stop to think about what the intrinsic idea of immorality actually means in the mind. In a way, if our brain reacts to something that can be called immorality in a particular way, these reactions define our personal views of what is moral or immoral, sifting the general accepted beliefs of society through the filter of our own psyche.

A recent study published in Frontiers in Evolutionary Neuroscience attempts to pin down whether there is a consistent activity pattern in the brain in response to “immoral stimuli.”

The study’s subjects were presented with verbal and visual stimuli, for example, relating to incest, violence, and many acts generally considered immoral. For control purposes, individuals were also given non-immoral stimuli.

Verbal stimuli included the following:

Sexual immoral acts — You giving your sister an orgasm, you watching your sister masturbate, you fondling your sister’s nipples.

Non-sexual immoral acts — You burglarizing your sister’s home, you killing your sister’s child, you knocking your sister down the stairs.

Researchers found a consistent left-hemisphere bias for processing different kinds of immoral stimuli. Interesting as the results may be, this is only the tip of the iceberg. The implications of understanding how the brain actually processes immoral stimuli could have a tremendous value for both neurological study and psychology. Opening up multiple possibilities for future research, the study pointed to a consistent pattern of brain response to “immorality,” as the left-hemisphere activity was observed in the case of both sexual and non-sexual immoral stimuli.

While the study of reference was carried out on healthy individuals, Dr. Robert Hare, a researcher who studies psychopathic behavior, measured the brain activity of psychopaths when exposed to different kinds of verbal stimuli. He found that the brain activity in psychopaths showed no variations when this type of subjects were exposed to words like “cancer” and “death.” These findings are consistent with the idea that words don’t carry as much meaning for psychopaths as for healthy people, hence their ability to lie and manipulate others.

The brain doesn’t process moral and immoral thoughts the same way under different circumstances. Curiously, a study from earlier this year showed that drinking something bitter deepens the perceived immorality of a certain event. When researchers asked a group of undergraduates to rate their moral distaste for various acts generally perceived as distasteful, including bribes, shoplifting, a man eating his dead dog, and two second cousins having sex. During the questioning, subjects were offered bitter, sweet or neutral drinks, the latter being water. The moral disapproval was 17% greater for those sipping bitter drinks, pointing to a possibly much greater influence of sensory experiences on our perceptions of immorality than we might have ever imagined.

Aside from the somewhat humorous fact that it might be better to offer people a sugar-packed drink before confessing a slip from morality’s path, it would seem that mapping out immoral thoughts in the brain could even lead us to identify people who might be more prone to committing immoral acts. However, the portion of what happens in the brain that we currently understand is still so little, that we won´t be seeing anything like the prescient murder convictions depicted in futuristic movies like Minority Report anytime soon.


Cope, L., Borg, J., Harenski, C., Sinnott-Armstrong, W., Lieberman, D., Nyalakanti, P., Calhoun, V., & Kiehl, K. (2010). Hemispheric Asymmetries during Processing of Immoral Stimuli Frontiers in Evolutionary Neuroscience, 2 DOI: 10.3389/fnevo.2010.00110

de Oliveira-Souza, R., Hare, R., Bramati, I., Garrido, G., Azevedo Ignácio, F., Tovar-Moll, F., & Moll, J. (2008). Psychopathy as a disorder of the moral brain: Fronto-temporo-limbic grey matter reductions demonstrated by voxel-based morphometry NeuroImage, 40 (3), 1202-1213 DOI: 10.1016/j.neuroimage.2007.12.054

Eskine KJ, Kacinik NA, & Prinz JJ (2011). A bad taste in the mouth: gustatory disgust influences moral judgment. Psychological science, 22 (3), 295-9 PMID: 21307274

Image via Csaba Peterdi / Shutterstock.

Veronica Pamoukaghlian, MA

Veronica Pamoukaghlian, MA, holds a Masters in Creative Writing. She has directed two documentaries shot in psychiatric wards and a feature documentary about the 77-year old senior Decathlon champion of the world, Raul. Her last production is Monstruo, a short film about non-voluntary euthanasia. She is the CEO of Uruguayan film production company Nektar FIlms. You may visit her blog at The Wander Life
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