 Under the course Trends and Issues in Early Childhood Education, now we will see the Biological System Theory of Human Development. Bronfen Brenner in 1979 organized context of human development into a set of five inter-related levels called the Bioecological System Theory of Human Development. Bronfen Brenner gave us the theory of five integrated systems in which the child learns. The first one is the Microsystem, which is the circle of your family and your home. The first one is the Microsystem, which teaches behaviors and attitudes, languages and manners. Then is the Mesosystem. If you go out from your family, the environment of the heart is in the Mesosystem. If you are in a neighborhood, a park, and then in the long term, you will go to school or become a part of an ECC program, then there will be more interaction with some people. This is your Mesosystem. There are stages of sociability, as I am saying. The first one was the home. It was a stage. Your relationship can be from 8 to 12 or all the individuals. If you go out, it can be up to 50 to 100 individuals. This is your Mesosystem. Then the Exosystem. This is your community. Sometimes you are going on a celebration, somewhere to travel, or if you are a community function that you are a part of, then there is more interaction. You deal with more people and learn to deal with them. Then is the Microsystem. The Microsystem is the whole world. Hold the universe, your universe. Where do you live? Which country do you live in? What is your identity in the whole world? What is the global community? What are the human rights of the people? The next one is the Chrono System. The Chrono System actually works within all these previous systems. This is your age. Along with time, along with age, in your sociability and in your social skills, it keeps increasing. That is, if you have come from your family, from school, from school, from community, from community to the whole world, then it takes time too. So as your age increases, similarly, in your sociability, in your understanding, in dealing with people, there is a difference. So each level of Bronfenbrenners' bio-ecological system theory of human development is connected to the others. Now these are not isolated systems. Each system gives birth to others. The next system that I have learned, the Mohartas, it works in that system. And then they are interrelated. They come back from there. For example, it is not that I have taught my family's system. After that, our child went out. He has learned some more things in the school system. So now the things that are learned from the school cannot be taught at home. Those who have taken culture from outside, those who have learned manners from outside, they will also come back to the family. Exactly the same way what he has learned from the global community will also bring it to his contextual internal community. So all these systems are interrelated. And what does this do? They act in both ways in the future. That is, you apply your values and your skills in a bigger system. And in a bigger system, you bring things back to your smaller system as well. So now we have seen that in this way, sometimes there are disturbances. I mean, you have taught your children a lesson that you have to respect someone. You have to speak well. You have to help others. You don't have to harm anyone. You don't have to kill anyone. You don't have to steal anything from anyone. You don't have to steal anything. But when that child goes out and sees all these fights, fights and abuses, he will come back and disturb your circle. So that is why we understand that to create a good leader we have to keep all the systems in mind. And we have to create coherence between them. Whatever they have learned at home, they should go out and act. And what they have learned is to bring back the selected things that are good and bad. So this is the demarcation that we have to make.