For many, a common sound suddenly starts making them angry. Several parents have said that all of a sudden their child exploded when they heard a certain sound. So misophonia may seem to happen automatically, like someone turned on a light switch, but data support the view that misophonia actually develops in individuals through experience with the world around them.
Genetics and Misophonia
Research indicates that there are genetic factors that make one person more likely than another to develop misophonia.28 One study found that individuals with Sensory Processing Disorder (SPD) were more likely to develop misophonia. SPD is primarily a genetic condition, so if a child has SPD genes, they are more likely to develop misophonia. There are other genetically influenced conditions, such as anxiety and bipolar disorder which have strong genetic factors. The more often a person experiences distress, conflict, tension, etc., the more likely they are to develop misophonia. I discuss this in more detail in the chapter Misophonia and Children. There are definitely genetic factors that make one person more likely to develop misophonia that another. We all probably know people who are almost always calm, and others who are easily irritated/distressed. A person who is almost always calm is not very likely to develop misophonia (noting that outward appearances can be deceiving). But genetics alone does not cause misophonia.
Environment and Misophonia
Even though there are genetic factors, it still requires experience with the trigger sounds for misophonia to develop. But, somewhat surprisingly, it doesn’t take long to develop a misophonic trigger.
I initially thought misophonia was caused by some traumatic event. I was wrong. People told me things like, “I sat by my grandmother in church and she was sniffling and her sniffling became my first trigger.” Another person told me that they developed misophonia to their stepfather chewing his food, and that they dearly loved their stepfather (no trauma here).
A woman shared that when she was a little girl, her brother would smack his lips, and their dad would reprimand him. Brother smacks the lips, daddy yells at brother; brother smacks his lips, daddy yells at brother. So brother smacks, daddy yells, she cringes (a physical/emotional response). Because she was a sensitive little girl, she was experiencing this physical/emotional response that went with her feeling, “Don’t yell, Daddy.” Her lizard brain began pairing the sound of her brother smacking his lips with her physical response that happened when daddy yelled. Her lizard brain learned to respond to her brother’s lip smacking at the dinner table, but the first trigger she remembered was her brother smacking his lips while eating pancakes at breakfast. At the dinner table, her response was to daddy being upset, but at breakfast, daddy wasn’t there. There was nobody to yell, but her little lizard brain heard the smack and jerked her body, and the misophonia emotions flooded into her brain.
The following are some cases that illustrate how misophonia can develop.