Wellness Blog

What are Instincts and Where Do They Come From?

Learn about what instincts are and the multitude of ways in which you might experience instincts every day.

Instincts are defined as the tendency to make complex and specific responses to environmental stimuli without requiring thought or reason. They have been described as “evolution’s ancient tool for prodding us in the directions that maximize our reproductive success” (Wallenstein, 2009). In other words, instincts are those behaviors that have helped a species survive over the course of evolutionary history.

For example, geese developed an instinct to imprint on the first moving thing they see as hatchlings (Scheiber et al., 2013). This instinct helps these geese bond to their mother whom they will rely on for food and protection for the first period of their lives. If they weren’t instinctively compelled to stay close to their mother, they would be less likely to survive and thus less likely to reproduce.

Humans are born with similar instincts that increase our likelihood to live long enough to reproduce. For example, when confronted with a threatening situation, we are instinctively driven to either face and fight the threat or flee and remove ourselves from the situation.

Instinct Theory

Instinct theory is an account of human behavior that suggests the motivations for our behaviors are completely or predominantly inherent in our biology. In other words, this theory proposes that we are born with the drives and motivations that shape our daily behavior. For example, this theory would suggest that your motivation to go out with your friends even when you’re tired is the product of your biologically assured instinct for social connection.

This theory also proposes that all motivations are primarily driven by an instinct to survive. In other words, our basic instinct is to keep living and every other instinct is in some ways a product of our most basic motivation.

Examples

Instincts are something we experience every day. We can find examples of instincts playing out in our own behaviors and in the behaviors of other animals. Here are some examples:

A baby's reflexes: Babies are born with the ability to engage with parts of the world around them and respond appropriately to stimuli. For example, when the corner of a newborn’s mouth is touched they instinctively tilt their head back so that they are better able to find their mother’s nipple (Bennett et al., 2020).
Migration of animals: Many species of animals, such as birds, butterflies, whales, and sea turtles, have an innate ability to migrate to particular locations at specific times of the year. For example, Caribou can migrate over 2,000 miles every year as the seasons change to find regions appropriate for birthing calves, finding food, and escaping mosquitoes.
Hunger instinct: When we’re hungry, we’re motivated to seek food. The adaptive advantage of an instinct like this is probably pretty obvious.
Pleasure instinct: We are motivated to seek out things that feel good and reject things that feel bad.
Social bonding: Many animals, including primates, have an innate ability to form social bonds with other members of their species. This helps them to survive and reproduce by working together to protect themselves and their offspring.
Grooming: Many animals, including primates, have an innate behavior of grooming themselves and other members of their group, which is important for maintaining hygiene and social bonds.
Self-preservation: Instincts that lead animals to protect themselves from danger, such as avoiding poisonous or dangerous food, or escaping from predators.

Gut Instincts

If you’ve ever reflexively stretched your right arm across your front seat passenger when making an abrupt stop or quickly scooped up a baby as it crawled toward a fire, you’re familiar with gut instincts. Though we might think we are speaking in metaphor when we talk about having a gut reaction, current research suggests that this might be a more literal event than we imagine.

Our stomachs actually have their own nervous system of over 500 million neurons (Furness, 2012). This is the largest collection of neurons outside the brain, which is why it is sometimes referred to as the little brain or the second brain. The nervous system in our guts is connected to our brains. This union is unsurprisingly called the gut-brain axis. The gut-brain axis is known to play an important role in our emotions and some of our behaviors.

Recently, scientists have discovered that the gut-brain axis is controlled in large part by tiny bugs that live in our stomachs (Dinan & Cryan, 2017). Studies have shown that these little gut bugs, collectively known as the microbiome, are involved in stress responses (Konturek et al., 2011), symptoms of depression (Dash et al., 2015), and social behaviors (Desbonnet et al., 2014).

There is also evidence to suggest that the microbiome can influence the brain mechanisms underlying emotional memory and decision-making (Bagga et al., 2018). This function of the microbiome may be responsible for the gut instinct we have when we are deciding whether or not we want to enter that spooky house by ourselves or if we should say yes to a marriage proposal. Though we don’t yet know exactly what gut instincts are, we can say that our guts are likely smarter than we think.

Summary

Instincts are pre-programmed behavioral responses to environmental stimuli. Throughout the evolutionary history of the animal kingdom, instincts have been a critical mechanism functioning to support the proliferation of a species. There is a vast array of instinctive behaviors ranging from the migration of butterflies to a human seeking out an activity they enjoy.

References

Bennett, R., Lashley, L. K., & Golden, C. J. (2020). Newborn Reflexes.
Dash, S., Clarke, G., Berk, M., & Jacka, F. N. (2015). The gut microbiome and diet in psychiatry: focus on depression. Current opinion in psychiatry, 28(1), 1-6.
Desbonnet, L., Clarke, G., Shanahan, F., Dinan, T. G., & Cryan, J. (2014). Microbiota is essential for social development in the mouse. Molecular psychiatry, 19(2), 146-148.
Dinan, T. G., & Cryan, J. F. (2017). Gut instincts: microbiota as a key regulator of brain development, ageing and neurodegeneration. The Journal of physiology, 595(2), 489-503.
Furness, J. B. (2012). The enteric nervous system and neurogastroenterology. Nature reviews Gastroenterology & hepatology, 9(5), 286-294.
Konturek, P. C., Brzozowski, T., & Konturek, S. J. (2011). Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. J Physiol Pharmacol, 62(6), 591-9.
Scheiber, I. B., Weiß, B. M., Kotrschal, K., & Hemetsberger, J. (Eds.). (2013). The social life of greylag geese. Cambridge University Press.
Wallenstein, G. (2009). The pleasure instinct: Why we crave adventure, chocolate, pheromones, and music. John Wiley & Sons Incorporated.