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...

 The Past and Who Has Access to It

What we know about the past—and who has access to such knowledge—has changed dramatically with each such change. The changes run far deeper than the mere proliferation of data points. As written records of large estates held in monasteries in France achieved legal and social dominance, the role of women as the tellers of the past fell into decline (Geary, 1994): The technological and the social were deeply intertwined. The outcome was that different kinds of records were kept. With the invent...