Biology and Being Alone

For a long time (really all of time, until recently) loneliness was always considered to be a psychological emotion; however, new studies published in the last few years questioned this assumption and discovered that there is a genetic link to loneliness. Not only did they discover that loneliness is partially genetic, they also discovered that it can increase a human’s risk for mortality. You read that right, a genetic response that is (assumed to be previously) linked to survival could actually kill someone. So, what is loneliness? Why and how do people get lonely and/or stay lonely? And what is it about loneliness that is so peril to humans?

First, it is important to define two very closely related terms that will be used frequently: loneliness and isolation.


  1. Being without company or cut off from others
  2. Not frequented by human beings
  3. Sad from being alone
  4. Producing a feeling of bleakness or desolation


  1. To set apart from others

Loneliness and isolation have a square – rectangle relationship. This is to say that being isolated can make someone feel lonely; however, not all lonely people are isolated. Isolation is not necessary for feeling lonely, but isolation can (and typically does) lead to experiencing loneliness.


Loneliness, John Cacioppo argues, is “an aversive state that [humans] seek to resolve” (Singer). Loneliness isn’t really a feeling of its own; the thing that compels us to create relationships/ companionships is the pain we experience when we are alone. Cacioppo, who is the Director for the Center for Cognitive and Social Neuroscience at the University of Chicago, says that “what we inherit is not loneliness, it’s [our sensitivity to] the painfulness of the disconnection.” It’s estimated that about fifty perfect of a human’s level of sensitivity to loneliness can be linked to their genes. His theory suggests that there is a biological mechanism, in our brain, that makes us feel bad if we’re alone and relief when we’re with others. The thing that is thought to do this is Dopamine. (Perhaps you remember Dopamine’s role in my previous post?) Along with signaling pleasure, it also motivates us to search for what we desire. Steve Cole, a genomics researcher at UCLA, says that “it is not what happens after you get what you want, it’s what keeps you searching for something.

Blackboard with the chemical formula of dopamine


Dopamine makes up roughly 25% of the dorsal raphe nucleus region of the brain. (Most of the neurons in this region – which is said to be linked to depression – produce Serotonin). Gillian Matthews, a researcher at MIT, conducted an experiment on mice in which she genetically engineered their dopamine cells to respond to particular wavelengths of light; this allowed her to be able to control the stimulation of the cells by exposing the mice to light. What she found was that when she stimulated the dopamine the mice appeared to enter a state of loneliness (acting as they would if they were isolated without stimulation) and it made them feel bad. Most mice avoided the stimulation (if they had the choice) as if it were physical pain. She also found that when she stimulated these neurons, (socially) high-ranking mice showed the strongest reaction and would search for companionship more intensely than the lowest ranking mice. This is because, Matthews hypothesizes, “… the [dorsal raphe nucleus] neurons are somehow tapping into that subjective social experience of the mouse, and only producing a significant effect on the behavior of mice who perhaps previously valued their social connections, rather than those who did not”.


Similar to MAOA (which is discussed in my previous post, ‘Nature, Nurture, Murder’), humans (but this could be extended to all animals if you consider the experiment done with mice) have varying degrees of susceptibility to (the pain of) loneliness. While this may possibly be due to varying levels of dopamine and other chemicals in the brain, researchers have been able to find an evolutionary benefit for this – which may explain why those levels of variability still exist in humans today.

Cacioppo says that we have survived as a species because of social protection (our ability to work together and communicate). If you go all the way back to the early days of mankind, there is evidence that this ability to communicate and work together allowed humans to be able to hunt down large mammals (that have dominance over us on the food chain). Working in conjunction with the ability to communicate and work together is varying susceptibility to loneliness. It is thought that people who were more susceptible to loneliness would stay at the camp – these people would maintain the camp, cook meals, make clothes and tools, etc. in close confines of other people (who are also more susceptible). This is because they had a greater desire to be around people and would choose to do tasks that allowed them to be close to camp and other humans. Those who were not as susceptible would venture out beyond the camp. They would go on journeys to map out the land around them, go on hunting trips, or other explorations. These people didn’t mind not being around people for periods of time, so they had no reserves on taking explorations. Eventually, most of these people would start to feel lonely and would return to camp, bringing with them any news or food they may have discovered. (So, you could say that a ‘sense for adventure’ is actually attributed to loneliness). This sort of two-part system, you could call it, is what is thought to have kept humans alive to this very day.

As I mentioned earlier, it is a highly accepted fact that loneliness is, at least partially, hereditary. Some studies have said that it is anywhere from 37-55% genetic; however, a very well-known study that surveyed over 10,000 people over the age of fifty found that only around 14-27% is genetic. The study says that loneliness (similar to physical pain) might be “part of a biological warning system that has evolved to alert us of threats or damage to our social body”. Louise Hawkley, a Psychologist at the Center for Cognitive and Social Neuroscience at the University of Chicago, with a similar tone says that “if loneliness was really bad [for us] it would have been bred out – so it must be adaptive”, but this statement turns up to only be partially true.

As time has progressed humans have gone from living in groups and being dependent to becoming predominantly more independent. In fact, we (humans and all of humanity) have the highest recorded rate of living alone that has ever been recorded. With that change in environment came a shift in how our bodies react to loneliness; in fact, it’s killing people. The Holt-Lunstad and Smith study found that the “heightened risk of mortality from loneliness [is] in the same category as smoking fifteen cigarettes a day and [/or] being an alcoholic”. One study by Brigham Young University found that the health risks for loneliness actually surpasses the health risk of obesity. And to make matters even more interesting, they also found that “the association between loneliness and risk for mortality among young populations is actually greater than among older populations. Although older people are more likely to be lonely and face a higher mortality risk, loneliness and social isolation better predict premature death among populations younger than 65 years”. In fact, they go on to that “loneliness increases a person’s risk of mortality by a shocking 26 percent! (On a side note: This information has led me to raise an eyebrow to the stats found in the study that only interviewed people over the age of fifty – perhaps something more extensive should be tested). This study included over three-million participants. The overwhelming conclusion in this study was that a lack of social connection increases a person’s health risk while having relationships and companionship has a positive effect. We are on the brink of what BYU is calling a ‘loneliness epidemic’.

So, does this mean that all of the anti-social people are going to drop dead?

No, not at all. A large misconception, identified by Meagan L. Knowles of Franklin & Marshal College, is that people become anti-social (or socially isolated) due to poor social skills (which completely vanish over time due to lack of use). What Knowles found is that lonely (or isolated) people do understand social skills, and usually out-perform non-lonely people when they are asked to demonstrate that understanding. What makes them anti-social (or keeps them lonely) is that they get choked-up when they are put in a situation where they have to use those skills because of fears and anxiety. What is Knowles suggestion on how to deal with this? “[lonely people] just need to get out of their own heads”! Just like other fears, the fears that increase a person’s feeling of loneliness can typically be combated with willpower. While some of the loneliness is genetic, there is a portion of it (and a large portion at that) that is not genetic. Which means that for most people (excluding those with extreme fears or anxiety) the ‘get out of your head’ method will work.

By this point you might be wondering, ‘well gee, I know that part of this is genetic, but is there anything I can do to keep from dying of loneliness?” Of course there is! Go outside, go interact with the world around you, and the humans and animals and things in this world. Don’t isolate yourself (too much). Get a roommate (if you don’t have one). If you’re really feeling like making a difference you can check out Oprah’s #JustSayHello Campaign or other campaigns that are similar. There’s plenty that you can do, just go out and do it!

Dopamine Image:
Dorsal Image:
All other images are property of Miranda Dean Images. MDI has full copyright.

7 thoughts on “Biology and Being Alone

  1. This post was honestly one of the most interesting out of all of the blogs I have read from our classmates thus far. The whole ideology behind the correlation between loneliness and depression, loneliness and eating disorders, loneliness and suicide has been something that researchers have gone back and forth with for decades. It was super interesting to read your perspective on a few of those topics and how you related it to a square and rectangle relationship. I also thought the 50% of loneliness being connected to genes part you talked about in your blog was really intriguing and got me thinking a lot. I’m definitely going to write about this topic and go off of a few of the ideas you started with because they are so interesting. Really awesome job, I really enjoyed reading your post!

    Liked by 2 people

    1. Oh my gosh, thank you so much!! I really appreciate you saying that! I’m really glad that this was able to give you a new perspective on the topic, and that it inspires you to do your own post on it. You write great blogs, so im really excited to read what you have to add to this! Doing research for this post was a rabbit hole of really interesting studies and information. The most interesting thing is (and I meant to add this to the post) the oldest study I could find was from 2015 (with the exception of John C who started his theory 10 years ago but had no evidence to back it up at that time)- so this whole concept is a very new. So there are a ton of new theories surrounding loneliness being genetic and what its really tied to/ contributes to. Im really interested to see what you find in your research!! Im so glad that you enjoyed this! 🙂

      Liked by 1 person

      1. I am really enjoying the conversation between you and Kaleigh! And the idea that social skills can vanish over time due to ‘lack of use’ is super interesting. So much of our behavior and emotions are largely a matter of ‘practice’, in spite of our genetic predispositions. Thanks for another fascinating post!

        Liked by 1 person

      2. Thank you! I think that one of the benefits of posting is being able to have these conversations in the comments and being able to read each other work and directly relate it to our own interests. I’m really enjoying it too!
        I think practiced behaviour is very interesting also! Did you read the article written by a man who was a test subject for NASA and spent 70 days laying down – he had to relearn how to walk after just 70 days of not doing it, despite having walked his whole life; it’s so interesting!

        Liked by 1 person

  2. I have not read that article- that is fascinating! Apparently both physical and behavioral traits need to be re-learned when they are out of use which makes sense since they are not really separate- the brain, nervous system, muscular and other physiological systems are all connected!

    Liked by 1 person

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