Before the advent of microarrays, scientists would have searched previous academic research for genetic links to other rude behavior, like talking in movies or standing in the express checkout lane with 25 items. They would have tried to form a hypothesis based on any previous research and tried to find a link to cell phone talkers.

Since the advent of the microarray, researchers can simply go to the genome and look directly at the DNA and see what that tells them. Researchers use microarrays to scan the whole genome and look for genetic similarities among a group of people who share the disease. Using microarrays to genotype 10,000 or even 100,000 SNPs, researchers can pinpoint the gene, or group of genes, that contribute to disease. For instance, if 500 people with the same disease all share a half dozen SNPs in common, but a group of 500 healthy people don't share those SNPs, researchers will start looking for mutations behind the disease around those SNPs. The SNPs don't give you the exact mutation, but they do tell you where in the genome to look for the disease-causing mutation. This approach is only possible through the use of high-density microarrays.