Instincts include fear, anger, shyness, curiosity and secretiveness among many more. Instincts are innate in all living organisms, from tiny multicellular bacteria and viruses to mammals and humans. Instincts are complex traits that ultimately help species survive, communicate and reproduce.
Fear is a basic instinct shared by humans and animals. Fear manifests in different forms from one individual to the next and is responsible for generating phobias such as fear of snakes, spiders, the dark and heights. Expressions and triggers of fear may change from childhood through adulthood because people learn to overcome once-feared objects or perceive new objects as threats instead.
Anger is another instinct shared by humans and animals. This instinct presents in several forms and is among the most varied instinct in the realm of expression. Some people physically express anger by shouting, glaring and turning red, while others clam up and become silent. Shyness and sociability are other instincts; some people are easily embarrassed and prefer spending time alone, while others are vocal and open in communicating. These individuals fall on the social end of the shyness spectrum. Curiosity and secretiveness are other complex instincts that vary widely in expression among individuals. These instincts are considered impulsive like shyness and sociability.