Chapter 11 - Reproductive Strategy
Nobody will ever win the battle of the sexes. There's too much fraternizing with the enemy."
Henry A. Kissinger

    There are two strategies that living things can use to create the next generation with the limited amount of energy they have available for reproduction: (1) They can invest that energy in a large number of progeny, putting only a little energy into each one so that, although most will not survive, there will be so many of them that a few will survive (an “r” strategy), or (2) they can invest that energy in only a few progeny, putting more energy into each one (e.g., as food in an egg, larger size at birth, body fat, milk, or care after birth), so that each one has a better chance of surviving (a “K” strategy). 1 Salmon, for example, have an “r” strategy, laying millions of eggs that are then abandoned; most die, but enough survive to make the next generation. An elephant, on the other hand, has a “K” strategy, having only a single 170 to 250 pound baby after 22 months of pregnancy, which is then nursed by the mother for three to five years. Most living things are in between the extreme “r” and the extreme “K” strategies. All humans have a very “K” strategy, but the races differ considerably in how “K” they are. 2
    J. Philippe Rushton has done a superb job of documenting racial differences in reproductive strategy (Rushton, 2000a), concluding that blacks are the least “K,” Asians the most “K,” and Caucasians in between, but close to Asians. 3 This racial order of reproductive strategy is a direct consequence of our evolution from a more “r” orientated ape. All the races descended from an ape; Asians evolved the most away from that ancestor, Africans the least, and Caucasians in between, but close to Asians. Table 11-1 presents a few of the traits that demonstrate racial differences in reproductive strategy. 4

Table 11-1
Trait Northeast Asians White Europeans African-Americans A: Africans
C: Chimp
Cranial sutures (1) Close late Close late Close earlier C: Still earlier
Eruption of wisdom teeth 5 1-2 yrs late (Japanese) Average Earlier A: 1-2 yrs early
Mean age of puberty (2) Later Pubic hair: 10.5
Breasts: 10.3
Menarche: 12.7
Pubic hair: 9.5
Breasts: 9.5
Menarche: 12.1
Gestation period (3) - Week 39: 33% born
Week 40: 55% born
Week 39: 51% born
Week 40 70% born
Twins (per 1000 births) 6 <4 8 - A: >16 (e.g., 57) 7
Triplets (per million) 10 100 - A: 1700
Quadruplets (per million) 0 1 - A: 60
Total fertility rate 8 1.6 (China) 1.5 (Can., all races) - A: 5.5

    (1) The sutures are where the bones of the skull meet. In a child, they are open and moveable but by adulthood they have fused. The sutures of Africans close earlier. 9 Late fusing sutures indicate greater neoteny (Schwartz, 2005, p. 131) and a more prolonged period of brain growth; sutures that close early indicate faster maturation. The sutures in Africans close earlier than in Eurasians. (Broca, 1858). The cessation of brain growth is consistent with IQ testing that shows increases in the intelligence of Negro children until about age 3, when they begin to lose ground (Chapter 14, FN 37 & FN 12, below); 2 year old Africans have an average IQ of 92, but it falls to 67 as they mature. (Lynn, 2006a, p 45).

    (2) (Wu, 2002). By age nine, 49.4% of African American girls start developing pubic hair or breasts, but only 15.8% of Caucasian girls. (Wu, 2002). Environment can affect the onset of menstruation; for example, vigorous exercise can delay it and obesity can accelerate it. (Kaplowitz, 2001). Growing up in a stressful home (e.g., no father, 10 violence, abuse) can lower the age of puberty and make girls more promiscuous. (Allman, 1994, p. 120).

    (3) (Rushton, 2000a, p 147). This is a large difference and is strong evidence that blacks have a less K-orientated reproductive strategy than whites. Black women have 3 times as many premature births as white women, even after adjusting for SES, and their median gestation period is two weeks earlier (31 vs. 33). (Kistka, 2007).

    In Table 11-2, the age of mother at birth is based on data from the National Center for Health Statistics.
Table 11-2
Race Age under 18
Births Under 19
(A) % of Population % of Race Number (B)% (B)/(A)
White 44.0 60.9 214,971 44.3 0.9
Black 11.4 15.8 122,175 25.2 2.2
Hispanic 12.4 17.2 127,402 26.2 2.1
Other 4.5 6.2 20,556 4.2 0.9

The last column shows that white and “other” teenagers have slightly fewer births than do adults of those races (0.9), but black and Hispanic teenagers have more than twice as many births as do black and Hispanic adults (2.2 and 2.1, respectively).
Table 11-3
Accomplishment African
Being drawn up into a sitting position, able to prevent the head from falling backwards 9 hours old 6 weeks
With head held firmly, looking at the face of the examiner 2 days old 8 weeks
Supporting herself in a sitting position and watching her reflection in a mirror 7 weeks 20 weeks
Holding herself upright 5 months 9 months
Taking the round block out of its hole in the form board 5 months 11 months
Standing against the mirror 5 months 9 months
Walking to the Gesell box to look inside 7 months 15 months
Climbing the steps alone 11 months 15 months

    Table 11-3 shows that right from birth, African babies are much more mature than European babies. 11 Although the author of Table 11-3 was attempting to show that blacks are superior because they mature faster, all of the activities in the table show faster maturation of the brain, which is associated with lower intelligence at maturity. 12
    Figure 11-1 (Geber, 1958, p 185-195) shows two of the tests:
    Faster maturation is also associated with faster population growth, and Africans have the highest population growth in the world, 13 now that Eurasians provide them with food and medical care. Despite wars, famines, AIDS, and the theft and waste of hundreds of billions of dollars, the population of Africa continues to explode. “In the United States the average woman will be a source of 14 children, grandchildren, and great-grandchildren; the comparable figure for an African woman is 258.” (Rushton, 2000a, p 161). This is exactly what one would expect from an examination of African reproductive traits.
Nine hours old, head doesn’t fall
backwards (white child, six weeks)
Two days old, holds head and looks
at adult (white child, eight weeks)
Figure 11-1

    African men have a stronger sex drive due to higher testosterone levels, a higher sperm count due to larger testicles, and behaviorally they have well-honed and fairly indiscriminate seduction skills. African women have a shorter gestation period, produce more multiple births, have fewer complications giving birth (due to fetus’ smaller head size and elongated skull), and African children become sexually mature at an earlier age and thereafter are considerably more sexually active than other races. Nigeria’s population, for example, doubled in just 25 yrs from 65 million in 1980 to 144.4 million in the middle of 2007 and is projected to reach 281.6 million by 2050, a 95% increase; only 4% of married women in Nigeria in 2003 with 2 living children said they did not want any more. (Population Reference Bureau, 2007 World Population Data Sheet 7). In the West, educated women have fewer children, 14 but educated women in Kenya who have already had 12 children have a 50% chance of having a 13th child. (Popp, 2000). The two global fertility winners are Somalia at 6.91 children per woman and Niger at 6.83. Meanwhile, the United States is just below replacement level (2.1) with 2.07, and a large proportion of those are not white. Figure 11-2 (Wikipedia, “Total Fertility Rate") shows the fertility rates around the world. The rate is clearly highest in Africa, which is consistent with the more “r” reproductive strategy of Africans.

Figure 11-2

Chapter 12

Table of Contents


1. (Rushton, 2000a, p 203; Levin, 1997, pp. 136-137). Back

2.  While the reproductive strategy is genetically determined, culture, the availability of food, and other factors can cause individuals to choose a more “r” or a more “K” strategy. For example, in the West, people are making a greater investment in their children (e.g., braces, medical treatment, college, keeping up with peers), necessitating a reduction in the number of children they have, a more “K” reproductive strategy. (“Increased Life Expectancy May Mean Lower Fertility,” ScienceDaily, Feb. 17, 2008). Although individuals will vary in how "r" or "K" they are, the mean "r-K" strategy of a population will tend to move towards the optimum for its environment. (Chapter 4, Rule 10). Back

3. An “r” strategy correlates with low IQ, tropical adaptations, poverty, and other traits, and a “K” strategy correlates with their opposites. (Andreev, 2004). Back

4. Data from (Rushton, 2000a, pp. 147-152) and elsewhere, as indicated. Back

5. (Olze, 2004). Also see (Harris, E.F., 1990; Davidson, 2001). Back

6.  Normal fertilization, not implanted fetuses or hormonally-induced multiple births. It is the mother’s race, not the father’s, that largely determines the rate of twinning. (Rushton, 2000a, p. 165). Back

7. (Rushton, 2000a, p. 165) citing (Bulmer, 1970). (Allen, 1987; Nylander, 1975). Back

8. Average number of children born to a woman during her lifetime. (Population Reference Bureau, 2006 World Population Data Sheet, "Demographic Data and Estimates for the Countries and Regions of the World"). The European rate includes a significant number of non-European immigrants. In most countries, fertility peaks among women between ages 20 to 24, but in nearly half of the surveyed countries of sub-Saharan Africa the peak extended to age 29 and sub-Saharan African women continue to have children at older ages than elsewhere. (INFO Project, Center for Communication Programs, The Johns Hopkins University Bloomberg School of Public Health, Volume XXXI, Number 2, Spring, 2003). Back

9. “The bones of the head are not only disunited, but are more or less overlapped at birth, in consequence of the largeness of the Caucasian child’s head and the smallness of its mother’s pelvis, giving the head an elongated form, and an irregular, knotty feel to the touch. The negro infant, however, is born with a small, hard, smooth, round head like a gourd. Instead of the frontal and temporal bones being divided into six plates, as in the white child, they form but one bone in the negro infant. The head is not only smaller than that of the white child, but the pelvis of the negress is wider than that of the white woman – its greater obliquity also favors parturition [childbirth] and prevents miscarriage.” (Cartright, 1857, p. 45). The large number of bones and their overlapping permit more growth after birth. (Broca, 1858, cited in Rushton, 2000a, p. 106; also see Chap. 11). Back

10.  The absence of a father can lower the age of puberty by 3 months, perhaps due to the absence of the father’s pheromones, but the onset of puberty in African Americans is not affected by the presence or absence of a father, possibly because the presence of fathers was not common in Africa. (Matchock, 2006). Back

11. (Wilson, 1978). Also see (Levin, 1997, p. 113; Freedman, 1969). “… the kinesthetic maturation rate [control of bodily movements] of native African infants was two or three times that of European children.” (Simpson, 2003, pp. 712-713). Faster maturation goes along with a shorter life span; both are a more of an “r” reproductive strategy. In 2002, African-Americans had 40.5% more deaths than they would have had with the white mortality rate. (A 2005 report by former U.S. Surgeon General David Satcher). The bodies of blacks mature faster. (İşcan, 1987). Back

12. (Shaw, 2006). Blacks are born shorter, lighter, and with smaller head perimeters; by age 7 they have caught up, but not in head perimeter. (Rushton, 1995). On the other hand, Chinese babies are also born with smaller brains, as Chinese women are petite, but the brain grows rapidly after birth, though the baby matures slowly. The gap in performance between Negro and white children increases with chronological age; the gap is largest at high school and college levels. (Shuey, 1966). “Young monkeys and young negroes are superior to white children of the same age in memory and other intellectual faculties.” (Cartwright, 1857, p. 45). “Young Negro children are nearly as intelligent as European children; but the older they grow the less intelligent they become.” (Hunt, 1864). “The monkey infant is better than the ape, and the ape better than the human, on such skills as grasping an object, reaching for an object, or sitting up unassisted. After 10 or 11 months, the superiority of the human infant begins to assert itself.” (Corballis, 1991, p. 69, citing Premack, 1988). “The intellectual progress of the Negro is rapid during the first ten or twelve years, next it slows down, becomes stationary, then proceeds slowly, diminishing during some fifteen years. Finally a rapid enfeeblement occurs.” (Professor H.V. Vallois, quoted in (Putnam, 1961, p. 52)). Quotes from (Hunt, 1864, p. 17): “Up to fourteen years of age black children advance as fast as whites.” (Sir C. Lyell). “[W]hen young, he [the modern Egyptian] is remarkably precocious in intellect, and learns with facility. As he grows up, his intellect seems to be dulled or diminished.” (Elliot Warburton). “[Africans] have a quick apprehension of the ridiculous, often surpassing the intelligence of the whites, and only drop behind them about the twelfth year, when the reflective powers being to have their assendency.” (Colonel Hamilton Smith). It’s not how fast you can go, it’s how far you can go. Back

13. For sub-Sahara Africa, there are 40 births, but only 16 deaths, per 1000 people per year. (Population Reference Bureau, 2006 World Population Data Sheet, "Demographic Data and Estimates for the Countries and Regions of the World"). Back

14.  Because educated women earn more, the amount of money they lose by having children, their “opportunity cost,” is greater. Back