Parastatistics is the study of how a population behaves and interacts with its environment. It looks at how a group of people or animals will interact in certain situations and how they might change over time. For example, if a group of people are living in an area with a lot of crime, parastatistics would study how this group of people would try to stay safe and how they might react over time to the changes in crime. It can also be used to study how different species of animals may interact with their environment or with each other.