The Scientific Portal of Behavior, Body Language and Nonverbal Communication#

Search for

May 31, 2012

Fear Factor

Fear is the fundamental and most ancient element that has driven all creatures on the edge for survival through different physical, psychological, mental and social adaptations. Perhaps, the way all living creatures look and behave today might be an ultimate result of long evolutionary history of continual battles with predators, parasites and environmental challenges. Don't forget to include struggle for resources and reproductive partners in those battles.

Wide open eyes let more visual clues pass to brain.

Even though we (major human population) no longer live in jungles and being surrounded by wild beasts, insects, worm, serpents and adverse climate; fear still influences and also helps us to survive in modern civilization. In fact, fear prevails in many forms and dimensions in personal - social lives, metaphors, concepts and ideologies. In fact, fear has given us strength to achieve and surpass beyond what other creatures on earth haven’t.

Long before we evolved in present form, fear helped our ancestors prepare themselves for fleeing or freezing under risky situations. Just Imagine if our hunting ancestors wouldn’t have run away from tiger attacking them in woods, they could not have returned to feed and protect their families in the first place. Thus fear serves the supreme purpose of survival in adverse conditions.

How brain triggers physiological changes under alarming situations is very interesting to understand. We react to fearful situation almost unconsciously only because of pre-programmed reflex that dates back to millions of years.

Facial expressions intensify with increasing risk.
Limbic System always monitors external parameters influencing survival and triggers fight, flight or freeze responses. It's the major part of our brain having some of very ancient circuits developed by our earliest ancestors living in oceans millions of years ago. Later, reptilian ancestors brought more sophistication in it.

Most recently developed analytical, planning and reasoning circuitry called as Neocortex (modern brain) that rests on top of limbic system cannot fully interfere with fight, flight or freeze responses in critical situations but it's same limitation serves a great purpose. If our ancestors would have spent more time watching, scaling and evaluating; predators would have wounded, amputated or killed them in a blink of an eye.

Tiger staring at a scared young man in Delhi zoo.
The tiger killed him later.

Obtained visual clues follow two routes to their destination triggering actual response; one is from eyes to Amygdale (center of emotional responses) through Thalamus (center of reasoning, learning and language abilities) and Visual Cortex (center of visual information processing) and another is from eyes to amygdale directly. In extreme dangerous situations, brain transfers signals from eyes to amygdale abandoning the process of understanding and analyzing situation.

Shortcut for Survival: Threat signals from Eyes to Amygdale

If brain would spend extra time (few more millionth fractions of a second) to activate an appropriate physical response, a fast moving and agile predator would exploit every opportunity to strike. Moreover, visual memories of deadliest encounters over from millions of years stored in Hippocampus (center of emotional memory) govern quickest reactions even in seemingly lower risk situations today.

Let’s find how what exactly happens in the human body under fearful situation. Parasympathetic Nervous System (one division of Autonomous Nervous System) starts sending signals to different organs through spinal cord. Adrenaline gland starts secreting hormone called as Epinephrine that prepares body to run away. First, it redirects large amount of blood-flow towards large muscles of our body and their supportive systems.

Heart beat goes up to supply more blood to various body parts that are responsible to run away and lungs engage themselves in increasing respiration rate for same. Blood flow is re-directed from non-essential to crucial parts of body like legs, stomach and abdominal area that’s why face appears faint (blood less).

Whole body dramatically shifts itself from calm, relax and confident mode to fugitive mode. Shoulders fall down and come closer whereas stomach gets pulled inside. Neck muscles get stiffer and chin drops to avoid damage to more sensitive parts connecting head with torso. Whole body starts sweating due to increase blood flow and excessive heat.

Muscles starts trembling due to body being locked at one location because they are initially prepared to run away with great energy generate by cells. Body bends down, clasps itself or takes shed of something. Feet are not firmly grounded and appear to mobilize body away from danger zone or attacker.

Face also synchronizes itself with body to collect maximum visual and auditory information to prepare for running away. Eyebrows tensely get curled downward and come closer on nasal bridge. Gaze becomes more focused and eyes are  opened widely to let more visual clues pass to brain. Mouth is wide opened to let more air pass to lungs. Throat gets dry and saliva’s swallowed frequently to moisten it. Voice trembles and person can hardy speak with usual fluency.

Sometimes, person tries to calm itself by blocking eyes and ears by hands. Same technique is used by zoo keepers to calm down animals after catching them. Eyes of animal are muffled by cloth to lower the level of anxiety pertaining continuous visual clues being sent to brain.

Comparing to evolutionary history of millions of years, human face evolved quite recently. Due to ability of speech articulation, it has an elaborate musculature compared to our primate cousins. The Expressions in lower part of our face (below nose) have evolved to communicate vulnerability to an entire group - to let others know about risk and seek help from them in return. Otherwise, there’s no any obvious purpose of mobilizing muscles in lower face to express fear.

Scream expels when person is under extreme threat so that if anybody is close to the person would take notice of it and rush for an immediate rescue. Another purpose of screaming would be to drive away the attacker or predator by shattering its ear drums with high pitch noise.

Sometimes, hands come close to mouth for muffling or suppressing scream in social situations. Indeed, an elaborate defense mechanism has developed in us over millions of years.

Related Articles:
1) Evolution of Nonverbal communication 2) "The expression of emotions in man and animals" 3) Survival of communicator 4) Basic Emotional Expressions 5) Body Language Brain 6) Inside Interrogation Room 7) Turtle Effect: Body response under threat 8) The Body Seeking Comfort 9) Surprise vs Startle Reflex 10) Basic responses in stressful situations 12) Body Language of Extreme Psychopath


  1. Fear keeps us cautious and even safe at times. It enables us to make decisions at times. However too much of anything is never good.

  2. Before we were feared in the jungle of snakes. Today in the home door for the invaders

  3. It is not the sympathetic branch of autonomous nervous system the one to activated the stress response?


Please post your valuable comment here.