Your genetic composition also plays a part in the Adult attachment style you may have developed. For example, in a study of saliva analysis, an Anxiety (A) attachment style was associated with dopamine receptors. You may recall that dopamine is a neurotransmitter that powers pathways in the extroverted brain (as opposed to acetylcholine that powers pathways in the introverted brain). Dopamine is often referred to as the “feel better” brain chemical, involved with addictive behaviors and the Brain Reward System, helping to manage emotions (50% is found in the GI System). An Avoidant (B) attachment style was associated with serotonin receptors. Serotonin is touted as both a hormone and a neurotransmitter. It acts as a neurotransmitter in the brain and nervous system impacting mood and sleep. In the GI system it can impact gastric secretions among other things (90% is found in the GI system).