Happiness and the evolution of brain size: Serotonin can act as a growth factor for the stem cells in the fetal human brain that determine brain size

Happiness and the evolution of brain size: Serotonin can act as a growth factor for the stem cells in the fetal human brain that determine brain size: https://ift.tt/37BdUD7 Read more... https://ift.tt/3kqwMIP