Final answer:
Negative assortative mating is when individuals mate with those who are dissimilar to themselves, which is the opposite of the definition provided in the question, making the statement false.
Step-by-step explanation:
Negative assortative mating occurs false when similar genotypes are allowed to mate. The correct definition of negative assortative mating is when individuals prefer to mate with partners who are genotypically or phenotypically dissimilar to themselves, which helps to increase genetic diversity within a population. Conversely, positive assortative mating is when individuals prefer to mate with partners that are similar to themselves, but this can increase the risk of inbreeding and is associated with harmful phenotypes due to the expression of deleterious recessive alleles.