Extraneous
An <em>extraneous variable</em> is a variable in an experiment that you are not intentionally studying. These variables usually provide undesired affects on the experiment.
In this example, the independent variable is whether a sentence is humorous or not, and the dependent variable is the memory performance score. However, because the humorous sentences are only given to males, and the non-humorous sentences are only given to females, gender becomes an extraneous variable as you are not intentionally testing gender's relation to the dependent variable, but it is still affecting the experiment.
Answer:
Social problems are usually present constantly, making it difficult to mark change.
Explanation:
Simply put, a social problem is any condition which affects a large number of people and is usually negative.
Therefore, the BEST Explanation as to why it can be harder to have an issue that impacts those in the lower realms of society defined as a social problem is that social problems are usually present constantly, making it difficult to mark change.
If you live near polluted areas you are more likely to get cancer. Like a home near a power plant. But if you live in a house with nature and plants around it or somewhere not polluted you have less of a chance to get cancer.