Answer:
Any study where group belonging is an independent variable or an inclusion condition.
Step-by-step explanation:
Every scientific study must have at least one independent and one dependent variable. Independent variables are the information we have and their values are not determined by other variables. Age, gender, height or weight could be independent variables. Dependent variables are the ones we are trying to predict or control based on the independent variables we have. If we use a group variable as either an independent variable or an inclusion condition, results could be generalized to the whole group and if the results are "negative" or undesirable socially, it could lead to stigmatization. For example, imagine a study trying to find differences in IQ between children from different ethnic groups. If there were differences to be found, some people might think the conclusion is some groups are smarter than others and it would definitely lead to stigmatization of the worst scoring group