The Science Behind Loneliness: Fresh Perspective

Are you scrolling through the magazine's Instagram page while standing alone in a secluded corner of the party while the intimidating known and unknown faces pop up in the disco lights? Or are you sitting by the dim lights of your bedroom on a regular Sunday eve? The feeling of being left out creeps into the filthy, squalid corners of your heart. Have we ever tried to find out the very basis of this ancient yet amplifying epidemic of loneliness? It's said that 25 percent of today's adolescents are the frontliners of the harm caused by this barbaric feeling. To speak scientifically might help us reach the very roots of the same or just help you in your next science project. Let's find out…

The antiquity of this feeling can be traced back to cavemen; evolution plays a major role in the upliftment of the original SOS signal of our brain. The cavemen hunted in groups, and the moment they got separated from one, they could potentially become the dinner of a wild wolf family; hence, this feeling of loneliness was a signal from the brain to let you find your group back. The feeling has evolved yet lived on from generations, from a caveman to you now in 2025.

Every emotion that plays through our mind is generated through a series of hormonal reactions; in this case, too, oxytocin and cortisol play the villains. Oxytocin (popularly known as the love hormone) is produced by the hypothalamus and released by the posterior pituitary. There is an opposite correlation between oxytocin and loneliness... Experiments in PMC articles show that the oxytocin level rises with better social interaction while decreasing in its absence. In turn, it also affects relationships and the bonding nature of a teen. The University of Bonn had also observed that the loneliness index decreases up to some percent when the patient is administered a spray of oxytocin hormone. These studies suggest that oxytocin not only responds to isolation but may be a target for interventions. It is a wild idea that science day would fix one of the most ancient and cruel emotions, and social anxiety might just end up being a myth.

Were you ever taught that loneliness is just in your head? Well, that’s proven wrong, thanks to cortisol, the stress hormone that’s pumped by our body in such situations. When there's too much, it messes with our melatonin and hence our 24-hour cycle; it often makes you prone to sickness and creates a sharp pain in your cardiac muscles. The increased cortisol impairs cognitive performance and increases the chances of vascular diseases. Some reports from experiments by NCBI show flattening of diurnal cortisol rhythm and less curvilinearity with an increase in the loneliness index. Once this loneliness is normalized and it almost becomes your daily routine, it may increase the CAR (cortisol awakening response); hence, the next day it shows a jump in cortisol response in you. These findings make cortisol a primary biomarker of loneliness.

The different parts of our neurological system are also affected by the level of loneliness and are involved in emotional processing and social cognition. The prefrontal cortex shows differential activation in various social structures. ss, the insula often shows greater activation when an individual is more likely to be isolated and depressed, and the hippocampus shows greater response during social exclusion tasks. The cerebellum shows a lower efficiency under isolated situations, and visual systems, too, show the same kind of behavior, proving the hypervigilance theory. Loneliness may also contribute on the brain's molecular level, contributing to neurodegenerative risks. Loneliness can also be genetic, as seen in twin studies, etc.; it has genetic correlations with almost 36 complex traits. The heritability of loneliness is said to be 4.2 percent, while debate still goes on about whether it is an independent character or not. The immune system is at high risk of collapse under severe loneliness syndromes.

But how are we measuring loneliness? Well, that could be a confusing and intriguing question. The best-known standard scale to measure it is the UCLA loneliness scale, which is a worldwide 20-question survey that has options 1 to 4. Scores are added at the end, and anything above 50 is severe and may lead to depression. One of the other famous scales is the  DE JONG GIERVELD loneliness scale that measures on two parameters—emotional and social connectivity. Sometimes people cannot really understand the questions, or sometimes they prefer to keep themselves locked up. In such cases, the physiological markers, like hormone levels, are used. The fluctuations in cortisol and oxytocin are primitive indicators. Recent studies have come up with another potential loneliness detector—it has been observed that active or passive time spent on social media is often in correlation with the teen's loneliness index.

Let me be clear that loneliness is also a part of human life, and anything in a controlled amount is not dangerous. We as humans, and especially growing teens, often lose connections and are unable to fully cope with it; hence, we take refuge under isolation and ghosting, etc. A little loneliness often acts as a sign for our mind to go out and make new connections while not forgetting the old ones; it keeps us grounded and lets us become the social beings that we are. It’s a bodily power bestowed upon us so that we get up, go out, and create a safe space for ourselves rather than expecting others to build it for us.

But anything in high dosage causes severe damage to not just the individual but to the family and friends of the same. Loneliness, if not taken seriously, often leads to chronic mental health disorders and suicidal ideations. It creates a mental loop where mental distress exacerbates isolation, worsening loneliness. Social isolation has severe effects on cardiac and neurological responses in an individual; it increases the risk of dementia and Alzheimer's. Reports often show that loneliness creates an addictive loop of drug and alcohol abuse among teens; it creates an undisciplined life and fatigue. It's important that the world studies more on such topics and correlations so that we can generate an escape from these uncertain loops that are often fatal.

But why are you reading a loneliness article after all? My main motive was to tell you the cool part, which is that it's often a chat with an old friend, a weekly visit to your nearby therapist, or even attending a family function that can lower this loneliness index and regrow a beautiful smile on your face. Notice, sometimes we are so engrossed in ourselves that we forget our fellow humans. I want you to notice every quiet kid in the class, a bullied child, or an old friend. Notice them, and you may as well save someone from one of the deadliest diseases in the world. Loneliness may not be contagious, but happiness is, and hence all we can do is be kinder and more gentle towards ourselves and others.