Arnold H. Buss & Robert Plomin 
Temperament (PLE: Emotion) [PDF ebook] 
Early Developing Personality Traits

Originally published in 1984, this title looks at the development of temperament in early life. At the time of publication there were three major perspectives on temperament: paediatrics, individual differences in infants, and inherited personality traits that appear in early life. Whatever the diversity of these perspectives, they converge on personality traits that develop early in life, hence the title of this book. The authors start by looking at the main research in this field, then go on to discuss their own approach to temperament, building on their original theory from 1975.