Humans have evolved over millions of years to have certain instinctive behaviors and responses. These instinctive reactions helped our ancestors survive and enabled our species to thrive. While culture, learning, and socialization shape human behavior, psychologists believe there are 5 core human instincts that are universal and deeply ingrained in our nature.
Fight or Flight Instinct
The fight or flight instinct is our innate response to perceived threats or danger. When we sense a threat, our body activates its sympathetic nervous system, triggering the release of hormones like adrenaline and cortisol. This speeds up heart rate, breathing, and metabolism to prepare us to either confront the threat or flee from it. Some key questions about the fight or flight instinct include:
What triggers the fight or flight response?
The fight or flight response can be triggered by both real and perceived threats. Some common triggers include:
- Encountering an aggressive or dangerous animal
- Being physically attacked or confronted
- Receiving highly upsetting or alarming news
- Getting into a serious accident or near-miss
- Being in a natural disaster like an earthquake or tornado
What happens in the body during fight or flight?
During the fight or flight response, the body undergoes many physiological changes, including:
- Increased heart rate and blood pressure
- Rapid breathing
- Muscle tension
- Dilation of pupils
- Release of glucose for extra energy
Is the response always helpful?
The fight or flight response evolved to deal with legitimate life-or-death situations. However, in the modern world, many of our threats are psychological rather than physical. Chronic activation of fight or flight can lead to issues like anxiety, insomnia, high blood pressure, and more.
How can we manage fight or flight?
Some tips for managing unnecessary fight-or-flight responses include:
- Deep breathing exercises
- Progressive muscle relaxation
- Getting regular exercise
- Meditation and mindfulness
- Cognitive behavioral therapy
The feeding instinct drives us to seek, acquire, and consume food. This instinct ensures we obtain the fuel and nutrients needed for our survival. Key questions about the feeding instinct include:
How does hunger motivate feeding?
Hunger provides the impetus for feeding behavior. As our stomach and intestines empty, they send signals to the brain stimulating food-seeking actions. Falling blood sugar and nutrient levels also create unpleasant hunger sensations that drive us to eat.
What controls when we feel hungry?
Several physiological factors influence hunger, including:
- Ghrelin – The “hunger hormone” produced in the stomach
- Leptin – The “satiety hormone” produced in fat cells
- Peptide YY
- Gastrointestinal contractions
How does environment impact feeding?
External cues can also trigger hunger and feeding behavior, including:
- The sight, smell, or taste of appetizing food
- Food advertising and media
- Social situations involving eating
- Times when we typically eat meals or snacks
What drives food preferences?
Factors influencing food preferences include:
- Genetic taste predispositions
- Familiarity and early food exposures
- Associations and comfort foods
- Nutritional needs
How do we know when to stop eating?
Satiety mechanisms that inhibit feeding include:
- Stretch receptors in the stomach
- Increased leptin and peptide YY
- Decreased ghrelin
- Rising blood sugar
- Fullness signals from the intestine
The sexual instinct drives mating, courtship, and reproduction. It ensures the propagation of our genes and the continuation of the species. Key questions about the sexual instinct include:
What physiological factors drive the sexual instinct?
Sexual desire and motivation are influenced by hormones like testosterone, estrogen, and oxytocin. Neurochemicals like dopamine also play a key role in sexual arousal and pleasure.
How does the environment influence sexual behavior?
External factors that can evoke sexual interest and responses include:
- Exposure to potential mates
- Privacy and intimate settings
- Romantic interactions
- Erotic stimuli
- Cultural sexual cues and norms
What are the evolutionary bases for mate selection?
Evolution has shaped some common mate preferences, like seeking partners who display signs of health, fertility, resources, and genetic fitness for offspring. However, many mate selection criteria are also learned socially.
How does sex drive change across lifespan?
Sex drive is influenced by age and life stages. Testosterone levels peak in adolescence and early adulthood, shaping heightened sexual interest during youth. Sex drive declines with advancing age but can remain strong into later life.
How do sexuality and attachment interrelate?
While the sexual instinct governs mating, our attachment instinct drives long-term bonds. Sexuality and emotional intimacy often interact to form loving, stable relationships like pair-bonds between parents raising offspring.
The parenting instinct drives caregiving behaviors that ensure offspring survival. While cultural factors shape parenting, the instinctive motivation to nurture our young is deeply rooted. Key questions about the parenting instinct include:
How does the brain mediate parenting behaviors?
Key brain regions involved in parenting include the amygdala, hypothalamus, and dopamine reward circuits. Hormones like oxytocin and dopamine shape caregiving motivations.
How does parenting change the brain?
Having and raising offspring prompts structural brain changes, like reduced gray matter and enhanced connections between emotion, reward, and cognitive regions. These support parenting aptitude.
What triggers caregiving toward the young?
Signs of infant needs like crying, smell, facial features, and attachment cues activate neural caregiving circuits, motivating nurturing acts like nursing, soothing, protecting, and provisioning.
Does paternal instinct differ from maternal?
Mothers undergo hormonal priming for parenting during pregnancy, supporting maternal behaviors after birth. Fathers show less automatic parenting responses but develop skills over time through caregiving exposure.
Does early caregiving impact later parenting?
Quality of parental care received in childhood shapes neural systems for parenting. Nurturing early experiences foster better parenting instincts later in life.
Humans have an evolved predisposition to form and live in social groups. Herding allows for collaboration on resources, defense, and childrearing. Key questions about the herding instinct include:
Why did a herding instinct evolve in humans?
Banding together in tribes offered primal humans key survival advantages, including:
- Collective foraging and hunting
- Shared food, shelter, and resources
- Improved protection against predators and threats
- Division of labor and roles
How does the brain mediate social needs?
The human brain contains specialized circuitry for managing social connections. Key regions include the temporal cortex, amygdala, fusiform gyrus, and orbitofrontal cortex.
How do we choose our social groups?
Group selection balances innate desires for belonging and self-preservation. We gravitate toward groups with shared values, goals, norms, identities, and reciprocal altruism.
Why do isolation and rejection hurt?
Being isolated or excluded from groups activates pain pathways and grief responses. Our primal herding instincts interpret separation as a threat to survival.
How has technology impacted social bonds?
Online networks now allow social connections beyond immediate tribes. But technology cannot replace in-person contact, which our instincts still crave.
While human behavior is incredibly complex, it is rooted in evolutionary instinctive drives that improved ancestral survival odds. The five core human instincts of fight-or-flight, feeding, sexual mating, parenting, and social herding continue to shape our thoughts, motivations, and actions today. These innate drives are adapted to promote self-preservation, reproduction, and group living. By understanding our instinctive human nature, we can better manage behaviors in our modern world.