Humans have and will always remain in the constant loop of evolution. A fact undisputed, nonetheless the metamorphosis that we go through, is evident from our progression which is both physical as well as psychological. Developmental psychology is one such field that deals with the scientific analysis of the behavioral changes that occur in people throughout their life. Initially, this field was centralized around the study of how infants and children portrayed behavioral changes, however, now it has diversified into finding out the circumstantial causes and effects of childhood on adults as well. Why some people behave in different situations differently, and why some people just seem overtly sensitive to seemingly normal incidences? The reason for this peculiarity seems hidden in the fact that, each individual is keyed according to the experiences and traumas that affected the course of their lives. Which is why this field of psychology tries to inspect and extract the tiny nuances, that might have had a decisive role in affecting the way some people behave. This field tries to help them improve their lives for the better. Let us find out exactly what is developmental psychology from this article. The main focus is to gather information about human development, through observation. It includes the study of the progress and behavior of humans from the womb until the grave. They focus on studying the progression as well as the factors that determine people's personalities, intelligence, genealogy, morality, and the way they approach and handle circumstances. This field has existed for centuries in some form or the other, wherein several theories of developmental psychology have been conceptualized by various psychologists. One of the most popularly accepted as well as protested, theoretical perspectives of psychology, was 'Childhood and Society', which was put forth by Erik Erikson in 1963. His work involved the study of human behavior in relation to themselves and their society, in a few basic stages. Here is what he stated in the 4 stages, which go on to affect the behavioral tendencies as adults:

• Stage 1 - Trust vs. Mistrust - This stage occurs from the child's inception, or his birth, up till the age of 1 year. Erickson believed that children develop a sense of trust or mistrust based on the way they are treated. They bestow their trust on those who fulfill their needs of food, comfort, protection, and sleep. If these are absent then the child would feel distrust towards the world, even in the long-run.
• Stage 2 - Autonomy vs. Shame - This stage dwells on the personality children develop between the age of 1-3, wherein children will be autonomous if their parents or guardians allow them the freedom to explore their curiosity, ask questions freely without fear of being reprimanded, and to be able to express their imagination without any hesitation. On the lateral side of the spectrum lies the verdict of shame. This emotion develops among children if their parents are overtly restrictive, strict, and stifling. These children find it hard to express themselves freely and when they do, they feel insignificant and fearful of the repercussions, and thus they develop introvert characteristics.
• Stage 3 - Initiative vs. Guilt - This stage unravels the personalities of children between the age of 3-6 years, wherein children try to do things with a sense of curiosity, and initiative. Sometimes they succeed and they feel good about themselves, but at times they fail or things go wrong, and they experience guilt. However, not every child is bound to feel these emotions in similar situations, because a lot depends on how parents deal with their children and treat them, which predominantly affects the personalities of the children. Parents who encourage their children to explore, and at the same time explain the disadvantages of doing something incorrectly, often raise children who develop a healthy and balanced persona.
• Stage 4 - Industry vs. Inferiority - The last stage deals with children between the age of 6-12. Herein, children at this age develop a sense of initiative as well as competency in all spectrum of their life. That may include, at school, among friends, as well as at home. Parents who help them grow and progress through words of comfort and encouragement, raise children who develop industrious personalities. While children who are discouraged and ridiculed by their parents for having failed, end up developing an inferiority complex. The children feel that they are constantly being compared with others, and that they are not good enough as individuals.

Jean Piaget's theory is based around human beings cycle of intelligence and the stages through which they have to pass through in order to gain knowledge. Knowledge is always being processed but need not be recorded in memory. This theory set up stages of how we acquire knowledge, construct it in our minds and finally how we use it, because we all use the given knowledge differently and for various motives as we grow older. According to this theory, thinking could be regarded as an extension of adaptation with the environment. Considered as one of the leading scholars of developmental psychology, Urie Bronfenbrenner's theory stated that development of a human being transcends 5 environmental systems. They were:

• Micro System: The micro system includes parents, school, pets, neighbors, and every other entity that is a part of an individual's daily life. These influences determine the way the individual will react to different situations.
• Mesosystem: Refers to interpersonal social relationships. For example, the relationship that one shares with parents and with school members. If the relationship is unsound at home, there is a high possibility that the child will have underdeveloped relationships with people at school etc.
• Exosystem: Refers to the indirect consequences that may occur in social settings, wherein the affected individual does not have an active role to play, nor do they have any control over the situation. For instance, if the husband is convicted of a crime and sent to jail, the wife and the child will be financially affected. There will remain only one earning member in the family, and all the financial burden will be for the wife to bear. There will be more arguments between the couple, and the child will not get to interact with his father often because of the jail sentence.
• Macrosystem: Macro system refers to the influence culture and country has on an individual's thought process and lifestyle.
• Chronosystem: This system refers to the influence of sociohistorical events on people. Such as, trends that change the socio-political aspects of people's daily life, example: how the recession affected the way people manage their finance and job opportunities.

Both these psychologists believed that real-world behavior patterns of humans was a stronger ground for research as compared to laboratory settings. Gibson's theory dealt with the fact that humans modulate and adapt their behavior as per the environmental settings in which they are placed. Which means that the same individual will have two distinct behavior when placed in two different situations. For instance, when placed among society, the individual's nature would be socially appropriate, whenever he/she is placed in a peaceful neighborhood, or a school. On the contrary, if the same individual is placed in a war zone, his/her first instinct would be survival, which could lead to appropriate behavior such as defensive or offensive reactions against the enemy. The theory revolves around the concept of 'Direct perception' which refutes the older school of thought based on 'Indirect perception'. Ecological psychology also rejected the concepts of cognitive view of human behavior as well as the theory of information processing, which believed in the latent information that all humans possess and manifest in the future. Gibson's theory believed that man behaved according to what he thought was the appropriate to that situation. Therefore, the basis of what is appropriate or not is conceptualized through observation and learning. Ironically, all theories except Gibson's, concentrate mostly on the developmental psychology of children, as experts believe it holds the crux to the personalities that these children develop as adults. Nonetheless, the importance of developmental psychology, may or may not appease everyone, as not all situations can be categorized as good or bad. Adults who have come from vastly dissimilar backgrounds may face similar situations which may change their perception about life. The fact remains that we are constantly changing and so are our thoughts, feelings, and opinions. Psychologists have helped many people move on with their lives, by allowing them to let go of their past experiences, which may have damaged the way they look and feel about themselves.