Michael Grant. The Rise of the Greeks. New York

Will Durant. The Story of Civilization

Michael Grant. The Rise of the Greeks

Oswyn Murray. "Life and Society in Classical Greece." In The Oxford History of the Classical World

Oswyn Murray. "Life and Society in Classical Greece"

John R. Skoyles. Darwin's last conjecture

Herbert M. Lefcourt. Locus of Control

Rene A. Spitz. "Hospitalism

True for lizards and mammals, which both have nervous systems as well as the chemical emitters involved in our neuroendocrinology. Not so true for bacteria, which possess the chemical and genetic triggers for shutdown and activation, but whose utility sorters have no neurological component. For more on how these mechanisms work in lizards and in the reptilian complex of the human brain, see

Jerome Kagan and Howard A. Moss. Birth to Maturity, a study in psychological development. New York, Wiley, 1962; A.A. Rosenberg, Jerome Kagan. "Physical and Physiological Correlates of Behavioral Inhibition." Developmental Psychobiology. December, 1989; Jerome Kagan. "Behavior, Biology, and the Meanings of Temperamental Constructs." Pediatrics. September, 1992; Jerome Kagan. "In the Beginning

Kagan's interest in Asian vs. American babies was triggered by the work of Daniel Freedman. See

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Alessandra Piontelli. From Fetus to Child

For related information on how twins are forced to assume different personalities by their competition and by their intensely emotional relationship, see

According to a study of 1,172 pregnancies, approximately one in 51 of us are conceived as twins. But only one in 106 of these conceptions results in the birth of two live twins. (E. Gerdts. "Ultrasonic diagnosis in abortion of one twin. The vanishing twin phenomenon." Tidsskrift For Den Norske Laegeforening. November 20, 1989

"The fetus may be striving mightily to glean an extra few percent of nutrient delivery from the mother, while the mother tries just as hard to prevent this." This is one of the many mother/fetus conflicts reported in

Alan G. Kraut and Sarah Brookhart. "Human Development

P.D. Wadhwa, C. Dunkel-Schetter, A. Chicz-DeMet, M. Porto, C.A. Sandman. "Prenatal psychosocial factors and the neuroendocrine axis in human pregnancy." Psychosomatic Medicine, September-October 1996

Much of the research in this area has been done on the manner in which uterine hormones feminize a male and masculinize a female, in the process affecting the development of the brain and of other central nervous system components. These, in turn, influence such personality characteristics as boldness, reticence, sexual preference and a great many others. See

S.M. Resnick, I.I. Gottesman, M. McGue. "Sensation seeking in opposite-sex twins

I am indebted to William Tillier, caretaker of Dabrowski's papers, for the following references on this subject

Jerome Kagan. Unstable Ideas

When a mixed sample of 100 working and middle class mothers were asked whether they thought physical affection was good for babies, almost all said yes. But when researchers gave the mothers essays either praising lots of physical affection or arguing that too much physical affection spoils an infant, the tract the working class mothers remembered best was the one on how physical affection spoils the child. Middle class mothers, on the other hand, recalled most vividly the essay praising physical affection. (Jerome Kagan. Unstable Ideas

Daniel Goleman. "New Research Overturns A Milestone of Infancy." New York Times, June 6, 1989

This comes from the work of Dr. Alan Dixson of Cambridge University and BBC producer Bernard Walton, aired on "Mask of the Mandrill," PBS, 6/12/98. Amplifications and clarifications used in this description were provided by Alan F. Dixson, personal correspondence, June 15-17, 1998. See also

Jerome Kagan. The Power and Limitations of Parents. Austin, TX

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

Jerome Kagan. Unstable Ideas

David Freeman Hawke. John D. - the founding father of the Rockefellers. New York

Xenophon. Spartan Society. In Richard J.A. Talbert, translator. Plutarch on Sparta. New York

Xenophon. Spartan Society. In Plutarch on Sparta