Psychology

Charles Darwin is considered as one of the greatest scientists of all time. His theory of evolution has continued to affect the various aspects of society in many ways. Though seen as controversial at the time of inception, this theory was later to be verified and subsequent research work has never nullified Darwins findings. Darwin himself asserted that the discovery of evolution theory was destined to reshape the field of psychology in a tremendous manner. This became a reality many years after his death as reflected in evolutionary and behavioral branches of psychology. The two disciplines borrow heavily from the evolution theory as stipulated by Darwin.

For many years philosophers had advanced the notion that life was initiated by a supernatural being that was beyond human understanding. This was based on the fact that nature was full of complexities and mysteries especially in regard to humankind and the functioning of their minds. This was before Charles Darwin came up with his theoretical framework that took the world by storm shaking the foundation pillars that had held the society for years. Darwin published his works The Origin of Species by Means of Natural Selection in 1859 followed by the Descent of Man in 1871 which marked a new beginning to how people conceptualized the world. Though his findings were vehemently criticized by the church, it had far reaching impacts in disciplines that were interested in the study of humans. Darwins concepts were borrowed in the study of psychology leading to the development of evolutionary and behavioral psychology. Though it is regarded as the youngest branch in psychological studies, evolutionary psychology has produced a great revolution in the field of psychology. This paper will focus on the contributions of Charles Darwin to the study of Psychology both in concept and methodology.

Charles Darwin
Charles Darwin was born in 1809 and is said to have developed an interest in the study of living things from an early age. In 1825, Darwin enrolled for a degree in medical studies at the University of Edinburgh which he gave up a couple of years later. In the year 1828 he enrolled for a theology degree in Cambridge University where he graduated in 1831. Darwins breakthrough began on the surveying ship HMS Beagle where he worked as a naturalist. During the voyage to the South America and Australian waters, Darwin made observations and collected plant and animal samples for his analysis. After the voyage, he began to develop his theoretical framework that would elevate him as one of the greatest scientists that ever graced the surface of the earth. In the year 1844, he began compiling the Origin of Species in which he argued out his concept of natural selection. His argument was based on the premise that life is characterized by struggles and competition in which case those that are well adapted can survive i.e., survival for the fittest (Loizos, 2003).

He was a naturalist who lived during the 19th century and is credited with the evolution theory. His theory of evolution is regarded as one of the greatest contributions to the scientific world and was published in the The Origin of Species of 1859. He applied this theoretical analysis in the work that was published in 1871 The Descent of Man where he hypothesized that man evolved from primates. These publications were met with controversy with the majority regarding them as insulting, atheistic, and irreligious. Later on researches were conducted on the issue with some of Darwins findings being modified and others being disapproved. Nevertheless, scientists acknowledge the fundamental idea of the Darwins thinking as they have been unable to refute his findings (Loizos, 2003).

Evolutionary and Behavioral Psychology
Human beings are said to be curious and that this curiosity is shared with other primates and forms the basic understanding of the success that has been achieved in the evolution process. This also forms the basis for natural scientific disciplines which includes evolutionary psychology. Evolutionary psychology is a discipline that focuses on the study of the human mind and how it is adapted to its functioning. Behavioral psychology on the other hand is concerned with the study of human behavior and how such behavior is acquired and developed. Evolutionary psychology tries to offer an explanation of psychological traits that are exhibited by humans which includes memory, perception, and language among others. These traits are seen as adaptations meaning that they serve as functional effects of the natural selection process thereby borrowing from Darwins concept (Buss, 2004).

 Evolutionary psychology has been described as combining two scientific disciplines which includes evolutionary biology and cognitive psychology. Others have expanded the definition of the discipline to include evolutionary biology, anthropology, cognitive science, and neurosciences. Thus evolutionary psychology is not like any other disciplines that focus on one aspect and can therefore apply to any topic in psychology. According to Tooby and Cosmides, Evolutionary psychology is simply psychology that is informed by the additional knowledge that evolutionary biology has to offer, in the expectation that understanding the process that designed the human mind will advance the discovery of its architecture (Barkow,  Cosmides, and Tooby, 1992, p 15).
Evolutionary psychology is therefore a scientific discipline that employs the scientific study of behavioral patterns in humans and primates by theoretically analyzing the evolutionary trend of such behaviors. This is different from the psychoanalysis that developed in Europe emphasizing on the inference of internal motivational states on basic drives. This has an impact on the study of behaviors in humans as behaviorists have to engage the influence of genetic traits on behavior. Charles Darwin can therefore be regarded as one scientist whose legacy shall continue to shape the field of psychology many years after he died. His observation that the theory of evolution will continue to shape psychological studies has in particular impacted on the behavioral and evolutionary studies in psychology (Craighead,  Nemeroff, 2002).

Darwins contribution to Psychology
In his work, On the Origin of Species, Darwin observed that, in the distant future I see open fields for more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation (Montgomery, 2009, para 1). This has come to be true considering the developments in the emerging fields in psychology such as behavioral and evolutionary psychology. Darwins theoretical framework in regard to evolution has profound effects in the study of human behavior. His methodology in particular when explaining human evolution and expression of emotions indicated how scientific experiments could be carried out through the use of data from various species in learning about the evolution of behavior. The comparative model is crucial in the studies carried out in evolutionary psychology (Montgomery, 2009).

Using the evolutionary approach in the study of human behavior lets researchers ask various questions in regard to a particular trait. The questions address comprehensive understanding of the trait in animals and they include four categories including the phylogenetic causes, ontogenetic causes, ultimate causes, and proximate causes of the trait. These questions helps one to understand the way a trait contributes to the organisms survival and whether it is the result of natural selection process or is a consequence of something designated to execute a new function. Using the evolutionary aspect to understand human behavior has opened new avenues in the psychological studies. Comparison of behavior in human infants and infant chimpanzees has been used in understanding of the development of social interaction. Other studies have focused on sexual desires, sexual orientations, choosing a mate, parental care and its development among other areas of interest. Such studies are helpful in the understanding of the existence of communities and how individuals arrive at decisions. Thus Darwins contribution to the study of human behavior is well addressed through such studies (Crawford,  Krebs, 2008).

The impacts of the evolution theory are still being felt in the world today as the implications of Darwins theorizing has gone beyond basic biology to incorporate other disciplines. Darwin had deep interest for psychology as revealed by his published and unpublished works. Having a good understanding of the classical philosophy, Darwin was interested in integrating his theory in the ancient metaphysical predicaments. In one of his notebooks, Darwin wrote Origin of man now proved  Metaphysics must flourish (Luttrell, 2009, para 3). He applied comparative methodology in trying to discover how human behavior evolved. He studied plants to understand simple behavioral adaptations and later on advanced to postulate that emotional expressions and moral sense were resulting from the evolutionary process. Darwin also made studies on the handwriting patterns in an effort to find any linkage between genetics and behavior (Luttrell, 2009).

Charles Darwin discovered that common response that humans have towards certain emotional conditions must have undergone evolution over the years. This made him ponder over whether facial expressions are based on instincts or on culturally learned responses. Though he did not live to accomplish this line of study, research that followed has revealed that indeed some emotions triggers universal facial expressions in all individuals. Generally, some emotions are known to trigger instinctive body movements which are biologically oriented and have been modified through the process of evolution. However, in most instances the instinctual responses are subdued by those societal rules that are learned which shapes the way individuals have to express their emotions. Humans have the capability to learn culture and thus learn the societal rules in a similar manner as to how they learn the language (Luttrell, 2009).

Contemporary evolutionary biology believes that genes are the building blocks that make up organisms. During replication, the genes carry with them all the character traits which are reflected in the genetic make up of the organisms. From the genetic make up, biologists are able to make some inferences in regard to the adaptability or mal-adaptability of the organisms in question. In this regard biologists are able to argue whether a particular trait is an adaptation to enhance the survival chances of the organism or not. Evolution biology is therefore a comprehensive analysis of Charles Darwin theory of evolution. Charles argued in his theory that those organisms with the best adaptive features shall endure the competition for survival. Evolutionary psychology on the other hand borrows from the evolutionary biology in the study of the human mind. This discipline may commence with an issue that has been recurrent in humans like those related to choosing a fertile mate, and explain the behavior. The fundamental premise of evolutionary psychology has been said to explain patterns of human behavior basing on the understanding that human beings are just like other organisms which have been evolving over the years (Curry, 2003).

Evolutionary psychology focuses on what humans do and the reasons behind their actions. The psychologists thus focus on the external behaviors or the internal motivations and this has led to development of the experimental and theoretical camps in the field of psychology. The experimental camp insists on making conclusions based on only the observable phenomenon through the empirical methods whereas theoretical camp is of the opinion that internal mental states forms the origin of human behavior. Darwin came up with a synthetic theoretical framework whereby he made both field and laboratory observations and used the findings to infer overarching rationalizations regarding the causes and effects of what he referred to as descent with modification (Maleuvre, 2001). He presented proof that indeed evolution took place and offered verifiable elucidation of the mechanism responsible for the evolutionary process. Evolutionary psychology has borrowed much from the Darwinian Theory since it aspires to provide a synthetic theorem that is composed of both meticulous and unbiased observations regarding how individuals behave. This includes the context of human behavior as well as explanations of the underlying causes of the respective behavioral patterns. Thus evolutionary psychology provides an indisputably unifying theoretical explanation of human behavior which is based on direct observation and can be applied to conceptual levels of human cognition (Grace, 2001).

Most of the explanatory concepts that have come up from evolutionary psychologist are drawn from simple observations in environments that are fully or partially controlled. This is also the case of the observations that are made by social psychologists as well as sociologists. Certain explanations in evolutionary psychology are related to the evolutionary theory in general. This includes the evolutionary biological theories that are abstracted from particular incidences. For instance, sexual behaviors and choosing a mate by evolutionary biologists has come from analyzing the observed data on the impacts of parental investments in offspring (Grace, 2001). Such theories have pointed to the need for scientific tests which has resulted in numerous and intriguing observations and inferences that have consequently suggested new theoretical framework. It should be noted that evolutionary psychology has stemmed from studies of other animals that are not human. Though this has been contested in some quarters, it must be appreciated that comparative studies of behavioral patterns in other animals are capable of providing remarkable insights in the study of human behavior. When such studies are successful, we can be able to infer the contexts and causes of certain behaviors. This may help in predicting the future which is the ultimate goal of any scientific undertaking. By understanding the causes of particular phenomenon, scientists are well positioned to anticipate the impacts and intervention program and satisfy the human curiosity (Maleuvre, 2001).

Conclusion
Ever since the inception of evolution theory, psychology was never destined to be the same again. Darwin noted that the discipline of psychology was set to undergo significant changes upon the revelation of his theoretical framework. Charles Darwins concepts of the 19th century can not be ignored in the field of psychology. His studies on the evolution of man and other species became profound in the 20th century with some scientists borrowing heavily from the theory of evolution to explain human behavior. In the 1960s and 70s, studies were conducted on the on animal and human behaviors which saw the emergence of a new discipline in psychology in then name of evolutionary psychology. Psychologists do not focus their studies on humans alone as much of their work is focused on the study of mother non-human animals. This is one of vital changes that were brought about by the evolutionary theory since Darwin also employed the comparative strategy in the study of the evolutionary process. In his studies he showed that even primates expressed emotions. Thus scientists are able to study animal minds using the comparative model in understanding the relationship between these animals and the humans. In psychology evolutionary concepts have revolutionized the field thereby allowing for various models to be brought together as one entity.