If anthropologists have a special advantage in trying to solve social problems, the advantage comes about because they are better equipped than people in other disciplines to clearly understand how a particular culture functions.
Anthropologists tend to immerse themselves in a culture. They typically live within the culture, trying to understand it through close observation of the people of that culture. By doing this, they arguably get a much clearer and more thorough understanding of a culture than people in other social science disciplines do.
This can give anthropologists an advantage in trying to solve social problems. Let us take the problem of domestic violence, for example. Anthropologists can use their thorough understanding of the culture to try to identify what, exactly causes domestic violence to occur in that culture. This might be in contrast to sociologists who can only identify which parts of the culture are more prone to domestic violence. By understanding the causes of domestic violence more clearly, the anthropologists are in a better position to suggest solutions that can effectively combat the problem.
Social problems are, by definition, the products of society. Since anthropologists understand societies more deeply than other scholars, they might have a particular advantage in trying to devise ways to solve such problems.