Psychology is the “science of mind and behavior”, Silverman (1874) defines psychology as "the science that seeks to describe and explain and on decision, to change the behaviour of man and other animals." Education also means change in the behaviour of an individual. So, education and psychology are as inseparable from one another as two sides of a coin. Without understanding the psychology of a child the teacher cannot educate him in the true sense of the word.
Psychology is the most important of the foundations of education. It plays pivotal role in the process of teaching and learning. The psychology used specifically in education is called educational psychology. We can say that both psychology and education are interrelated. Education is the shaping of behavior, whereas psychology is the study of how, when and Why to shape these behaviors.
Thus Educational Psychology is an applied branch of psychology that deals with the application of the principles of general psychology to the problems of education. We can, in more simple words, say that 'educational psychology', applies knowledge to educational problems.
Educational psychology explains the changes that take place in individuals in their various stages of development. It explains the effect of the environment on the child. It also studies the child's inborn emotions like anger and fear as they play pivotal role in learning and teaching.
The above definition of psychology shows that without the proper study of educational psychology it is impossible to impart education to children correctly. Psychology forms the basis for education. It is helpful in understanding the individual differences among children.
According to Pestalozzi the aim of education is the harmonious natural and progressive development of the pupil. To fulfill this aim the teacher must have an insight into the working of the child's mind. He must have the knowledge of various stages of child's life and their demands. He must know how to make a maladjusted pupil well-adjusted.
From the above discussion it is clear that education must have psychological foundation, that is, curriculum should be based on the sound principles of psychology. The curriculum of a level (class) must be in accordance with the needs and demands of the age of that level.