In my point of view Statistical application is the common line in both social and all other Sciences, If you remove statistics from social sciences, it is no more a science but others remains Sciences.,
In social inquiry, the reconsideration of application of methods of natural sciences, will clearly discriminate between the two. Let social reality be approached and explained by other perspectives. Let the social reality be understood by getting more closer to the holders of reality.
Clear demarcation or boundary is not possible because there exist an overlapping. Because social science is a group of academic disciplines that examine society and how people interact and develop as a culture. Social science as a field of study is separate from the natural sciences. Social science cover topics such as economics, political science, history, law and geography.
Drawing boundaries around domains of inquiry is not an activity in which individuals can engage: such boundaries, if they exist, are the result of how researchers in various domains of inquiry conduct their activities. We might want to ask why such boundaries might be necessary, what (and whose) purpose they might serve, and why we should worry about them. Each of us conducts research in our own areas of interest. Interesting findings have emerged at the intersection of specific disciplines, or when methods common in one field have been applied to another. A key difference between natural and social sciences is the existence of agency: electrons can be counted on to "behave" in specific ways (though we may not know them all yet) while humans respond to their own circumstances to the best of their (different) abilities. It is often perilous to approach social sciences in the same ways as natural sciences. Still, establishing boundaries between domains seems to lack general purpose (though it might serve specific individuals).