A recent study was attempting to determine a possible link between high levels of the brain chemical serotonin and aggression/anger. Instead, researchers stumbled upon an unexpected discovery.

In the study, mice were genetically engineered to overproduce serotonin. Most of the mice died at an early age because they were unable to regulate their body temperature and heart rate. The finding led researchers to believe that an overproduction of serotonin could be responsible for Sudden Infant Death Syndrome. SIDS, otherwise known as crib death, is one of the most common causes of death in children between the ages of 1 and 12 months old.

The studies findings support previous research which linked SIDS to abnormal production of serotonin.