Temperament is Influenced by Chemicals

Some 40 percent to 60 percent of the observed variance in personality is due to traits of temperament. They are heritable, relatively stable across the life course, and linked to specific gene pathways and/or hormone or neurotransmitter systems. Moreover, our temperament traits congregate in constellations, each aggregation associated with one of four broad, interrelated yet distinct brain systems: those associated with dopamine, serotonin, testosterone, and estrogen/oxytocin. Each constellat...

 Infant Behavior as a Key to Human Behavior

Staring at that skull, I was struck by the fact that this ancient child was somebody's baby long ago. Perhaps she was sick, or maybe he e was accident-prone, or perhaps this baby was some predator's dinner. Standing there, I could picture him or her long ago, I, smiling, laughing, and reaching out to grab a mother's breast. It was the most beautiful thing I had ever seen. From a biological point of view, the Taung child represents a specific stage of development for Australopithecines, our ...