530 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
siblings excluded in the three cases involved (Leibniz, Coleridge, 
Pope) were children by previous wives of their fathers. The im- 
pression produced by inspection is that there may be an excess of only 
and first children among these 20 geniuses. But an analysis of the 
probabilities does not favor this view very strongly. The average 
likelihood of being born in first place in the 20 families works out 
to about one-third, and the observed frequencies deviate from the 
theoretically expected only enough to yield a chi square of 2 in sup- 
port of the hypothesis; since this corresponds to a confidence level of 
between 0.2 and 0.1 for the one degree of freedom, one is left in 
doubt. Pascal, Niebuhr, and Adams were first sons. If we esti- 
mate in terms of first sons, a total of 13, and adjust the probabilities 
to the expectation that about half the children in multiple births 
would be girls, the chi square is 1.8, again too small to support the 
hypothesis firmly. 
Though the figures do not support a birth order hypothesis, there 
may nevertheless be something about position in the family which is 
significant. Let us look at the seven who do not rank as first-born 
children or first-born sons. Coleridge was born in his father’s old age 
and was his “Benjamin”; Voltaire was so sickly during the first year 
of his life that there was daily concern over his survival, and his 
mother, an invalid, was incapable of having any more children; 
Chatterton was a posthumous child, and the previous boy in the 
family had died in infancy; Mirabeau was the first son to survive 
after the death of the first and a succession of girls; Tasso was the 
only surviving son, his older brother having died before he was 
born; Pitt was in the interesting position of being able to follow his 
father in a parliamentary career in the House of Commons, as his 
older brother could not do so because of the inherited title; and Mus- 
set, the second of two sons, was younger than the first by a significant 
span of 6 years. When we weigh these additional facts, the general 
notion of some sort of positional effect begins to reassert itself. 
One way in which position in the family might favor the develop- 
ment of a child would be by giving it higher attentional value for the 
parents. Close examination of the biographical data leads to the 
conclusion that these 20 men of genius, whether because of their 
position in the family or not, did as children receive a high degree 
of attention from their parents, as well as from others. In several 
cases it is clear that the attention exceeded that accorded to their 
brothers and sisters. Both very decided and very positive parental 
interest was displayed toward Mill, Leibniz, Grotius, Goethe, Pascal, 
Macaulay, Bentham, Coleridge, Niebuhr, Adams, Wieland, Pope, 
Pitt, and Melanchthon. Voltaire and Musset were far from 
neglected, but the attention bestowed upon them may have lacked 
some of the intensity of focus notable in the preceding cases. If any 
