A “selector” is whatever increases or decreases the reproductive success of an individual because he has (or does not have) a particular combination of traits. With modern science and international aid, humans today don’t need to worry too much about selectors other than occasional germs and the whims of the opposite sex, but early humans were mercilessly brutalized by selectors far beyond their control. We should be grateful to them because without the terrible suffering and death they endured from these selectors, we would not have the traits we do today.
    A selector can be a cold climate that kills off those who lose heat too easily, a warm climate that kills off those who cannot lose heat fast enough, a predator that kills off slow runners, a bacteria that kills off those with weak immune systems, a competitor (perhaps even an individual in the same population) who is better adapted, and so on. If there are two sexes, the selector may be one or both of those sexes, who selects beautiful feathers, lovely songs, or weird appendages in the other sex. Even culture, if it alters reproductive success, can be a selector. Indeed, anything in the environment that affects reproductive success can be a selector, and that includes man, who may select for traits that he finds useful, “cute,” or otherwise attractive.

                           Climate
    Climate is the strongest selector, not only for humans, but for almost all living things, for the simple reason that it directly affects the amount of food available, which directly affects the number of progeny that can survive. Climate includes temperature, rainfall, sunlight, air pressure, oxygen and carbon dioxide content of the air, and how different the seasons are, all of which, in turn, determine the type and quantity of food that is available, when and where it is available, and how easy it is to obtain it.
    Humidity, rainfall, and the presence of predators and prey can change for a variety of reasons, but changes in the amount of energy useable by organisms, e.g. as sunlight, food, or heat, is critical. Temperature is a good surrogate for available energy. Temperature is affected by altitude (it decreases about 1°F for every 275 feet you go up) and warm ocean currents (it decreases about 1°F for every 5½° longitude you go east in Europe), ¹ but the amount of sunlight striking the earth’s surface has the greatest effect on temperature. The difference in the distance from the sun to the earth between the winter (91,700,000 miles) and the summer (94,800,000 miles) has less effect on the amount of sunlight than does the angle between the sunlight and the earth’s surface. The equator, which is more directly under the sun, receives much more sunlight than the poles, where the sunlight is at a small angle to the surface, if the sun rises at all.
    The point on the surface of the earth that is perpendicular to the sunlight traces a somewhat sinusoidal path across the surface of the earth that moves from the equator to 23° 26’ 22” north latitude (Tropic of Cancer, Figure 17-6, p. 147) in the northern summer, then back across the equator to the same south latitude (Tropic of Capricorn) in the northern winter. Except for rare catastrophes, the amount of sunlight striking any particular part of the earth has not changed greatly since the beginning of life on this planet, about 3.8 billion ya (Haywood, 2000, p. 13), but migrations from one latitude to another change the amount of sunlight a population receives.
    The average amount of sunlight over a year decreases with latitude away from the equator (reducing the average temperature about 1°F for every 70 miles you go north in Eurasia). More importantly, however, is the fact that as one moves from the equator to the poles, the difference between summer and winter temperatures increases to a maximum, then decreases again. In the temperate zones, where that maximum difference occurs, food comes in abundance at the end of the growing season, but during the winter edible vegetation is hard to find, though herds of large mammals may still be available.
    Catastrophic climate changes have occurred throughout the history of the Earth, from ice ages to impacts by comets to volcanic eruptions. ² Most occurred long before humans appeared and some affected only small areas. There were no major disasters due to comets or asteroids during man’s time on Earth, ³ but there were ice ages, glaciers, and rising and falling sea levels that affected the areas our ancestors inhabited.
    Mount Toba or “Toba,” as it is affectionately known, is a volcano in Sumatra, Indonesia. Today, it is peaceful and shows no inclination to devastate the planet, but 73,000 ya it was an angry beast, blasting 2800 km³ (671 cubic miles) of material into the sky, along with millions of tons of poisonous sulfurous gases, blackening the skies across the northern latitudes of the earth. The ash dropped in a northwest path across India, in places 18 feet deep. (Savino, 2007). Analysis of ice cores indicated the temperature dropped 61 Fahrenheit degrees in Greenland for about six years.⁴ Since Toba lies only 3 degrees north of the equator, the amount of energy reaching the earth for warmth and photosynthesis was drastically reduced. The resulting “volcanic winter” blotted out the sun, killing vegetation, then herbivores, then carnivores and humans. The effects were more severe in the northern latitudes, where winters already made survival difficult, but Toba did not have much affect on Africa. Some of the people affected by Toba were better able to cope with its effects than others, so Toba not only killed people, it altered the genome of the surviving populations, as we shall see in Chapter 20.
    There were two ice ages that affected the evolution of modern man, together referred to as the Würm glaciation period. The first ice age began about 73,000 ya, when Toba erupted, and lasted until about 55,000 ya. Although ice ages are attributed to changes in the Earth’s orbit (Hayes, 1976), it is quite likely that Toba triggered or accentuated that ice age by increasing albedo, the reflection of sunlight back into space from snow and ice. Temperatures fell and snow stayed on the ground longer before it melted, until it did not melt at all, but accumulated as thick glaciers that covered the land and inched south, wiping out most of the evidence that man had once lived there. The entire area north of India and most of West Asia north of the Caucasus Mountains was under a sheet of ice, but some of central China remained ice-free, giving East Asians a head start on Caucasians. Water evaporated from the oceans and fell as snow, no longer flowing back into the oceans, so sea levels fell, creating more shoreline and land bridges between continents and former islands. In Africa, however, there was no continental glaciation, ⁵ even near the southernmost tip of Africa, just “moderate fluctuations in climate” (Howells, 1959, p. 120), though there was drought.
    The movement of cold air and glaciers down from the north forced Europeans and West Asians to migrate farther south (less so in East Asia), no doubt creating conflicts with the humans already there. The Eurasian population fell drastically ⁶ and the selection pressure for cold adaptation was severe. ⁷ Those Eurasians who were better adapted for a colder climate had to migrate less, suffered fewer losses, and passed on their alleles for cold-adaptive traits.
    When warmer temperatures returned, the glaciers melted and the seas rose. The Bering Strait again separated North America from Asia. Shorelines and low areas were flooded, concealing evidence that man once lived there, and higher grounds again became isolated islands. Eurasians followed the receding ice north, increased their numbers once again, and re-colonized Eurasia.
    The second ice age occurred from about 30,000 ya to about 12,000 ya. It was more severe, but had less effect on man’s physical evolution because by that time man had culturally evolved (e.g., garments, constructed shelters) and was better able to cope with the cold. Sea levels fell again, 130 meters (427 feet) lower than today, giving Eurasians easy access to North America, Australia, ⁸ Japan, and Africa. The English “Channel” was dry land and one could walk from France to England and Ireland. (Sykes, 2001, p. 9). Although both ice ages severely reduced Eurasian populations, when temperatures rose again populations expanded greatly, and the coming of agriculture, about 12,000 ya, produced an even greater population expansion.
    Figure 5-1 shows volume of ice for the last 450,000 yrs. Note that from about 120,000 ya until about 10,000 ya the temperatures were much colder than they are now; the peaks of the first and second ice ages are indicated by the two arrows.

Figure 5-1

                             Sexual Selection
    After climate, sexual selection is the next strongest selector for humans. ⁹ Sexual selection means that the sexes do not mate indiscriminately, but preferentially select individuals who have certain traits. Because populations that have a more “K” orientated reproductive strategy (fewer children, more child care) pair bond more, they have more stringent requirements for their mates and therefore have more sexual selection than populations that have a more “r” orientated reproductive strategy (more children, less child care).
    Although both sexes do some selecting, especially in modern times, if the sexes are free to make a selection it will be the sex that has the most to lose by a poor choice that will select most cautiously, and that is usually females. ¹⁰ Because women need food not only for themselves, but also for their fetus and then their child, sex, at least until contraceptives came along, was very costly for them.
    Thus, the balance between male selection and female selection shifts according to how much of the food and other resources each sex provides. In Africa, the women, even today, farm and gather food, so they have more selection power, ¹¹ but in the colder climates more of the food was meat, especially in the winter, and hunting was done by men, shifting some selection power to men. (Miller, 1994a). As a result of selection by men, Eurasian women have become more beautiful ¹² and, as a result of selection by women, Eurasian men have become workaholics and slightly more intelligent than Eurasian women (more intelligence = a better provider in Eurasia). African women have become slightly more intelligent than African men, however, who have become the more physically attractive sex. ¹³
    The sex that has evolved a lot of superfluous traits, traits that are not useful in obtaining food, evading predators, and the like, but do appeal to the opposite sex, is certainly being sexually selected. For birds, it is almost always the male that has superfluous traits, as the male often has bright, colorful plumage and lovely songs that attract both females and predators; the superfluous traits tell females that the males must be of really high quality to be able to present such a display and not get eaten. Although the difference in beauty between men and woman is not as stark as between male birds and female birds, it is fair to say that, at least for Eurasians, the ladies have the edge in beauty, suggesting that men are doing some selecting of women, though women still do most of it. As (Coon 1962, p. 86) put it, “all females receive sexual attention. Among primates, [in order to reproduce] it is easier to be a female than to acquire one.” However, once meat became an important component of the human diet, the “meat for sex” trade ¹⁴ began to play a greater role and selection by men increased.

                          Selection by Women
    If a woman and her children don’t need a man to survive, she can choose a man who is handsome and charming, but likely to leave after copulation. In other words, she can choose a “cad” and, if she can do so without diminishing the survival chances of herself and her children, she is more likely to do so. The handsome, charming cads then have more offspring and pass their alleles for cad-like behavior on to their sons. ¹⁵
    On the other hand, if she is not capable of providing for herself and her children, she will have to be more practical and chose a man who is likely to stick around after sex and take care of her and her children, a “dad.” (Chu, 2007). Clark Gable for thrills, Joe Sixpack for bills. Of course, it would be nice if Joe Sixpack were also young, healthy, romantic, and had good genes, ¹⁶ but those qualities mean nothing if he does not provide for her and her children. Today, a woman can choose a man who can not, or will not, help her survive and the welfare state will force that man and other people (taxpayers) to provide for her and her children, but before the welfare state a woman who unwisely chose such a man would have a life of poverty and an early death.
    It has been suggested that women select men for intelligence (Ananthaswamy, 2002), ¹⁷ and that may have played a significant role in man’s evolution towards higher intelligence. Intelligence, as we shall see (Chap. 14), correlates well with wealth, so intelligence is a way to identify men who have, or are likely to acquire, the resources needed to care for a woman and her children. ¹⁸ High status men are also likely to have access to more resources, and so high status is a strong magnet for the ladies. (Pollet, 2007). But since women today have less need for the resources of men, many women define “high status” less as having money and power ¹⁹ and more as being “cool,” i.e., having currently-fashionable clothes, language, and behavior.

                           Selection by Men
    A man can impregnate many women and have far more children than can a woman, so a reproductively successful man can have a greater effect on the traits of future generations than can a reproductively successful woman. ²⁰ Although a man can rape a woman, thereby eliminating any selection on her part, in most societies rape is not a good reproductive strategy as pregnancy is hit or miss and the penalties for rape may be severe. ²¹ But for a man with low status and few resources, rape can be worth the risk. ²² Other male strategies include paying for sex (prostitution) and sincere or deceitful courtship. (Shields, 1983, pp. 117-119; Wrangham, 1996, pp. 131-146).
    If sex is going to cost a man little beyond an ejaculation he won’t be very selective. But if it is going to cost him a lifetime of support for a wife and children and possibly deter him from having sex with other women, ²³ he will select much more carefully. (Power, 2006).
    Since the better providers are desired by more women, but may not be able to support more than one, those men will select the woman they will provide for, and they will make that selection based on which woman they think will make a good wife and mother. ²⁴ If they do not select on that basis, their children are less likely to survive and men who lack alleles for careful selection will be replaced by men who have them. A good future wife and mother must have a pleasant, caring personality, be young (i.e., many years of child-bearing), ²⁵ healthy (i.e., capable of bearing and raising children), likely to be faithful (i.e., his children), and have “good genes.” Since good genes are required to make a face and body that are symmetrical and are not deformed or diseased, physical attractiveness is a good indication not only of health, but also of high quality genes. ²⁶ Paradoxically, Eurasian women owe their beauty not to the choices made by their mothers, but to the choices made by their fathers, grandfathers, etc. ²⁷

                            Group Selection
    A “group animal” is a species whose members live in groups, usually cooperating to obtain food. Wolves are the archetypical group animal, but probably from the first primates and for millions of years thereafter the animals in man’s lineage have been group animals at least as much as those in the wolf lineage. Group behavior is still deeply ingrained in our genes and we see it today in how readily we form groups and how important it is for us to be accepted by others in our groups. Allegiance to a group arose because individuals who acted in concert with their associates for their mutual benefit, especially in conflicts with others, were more reproductively successful than those who did not.
    For a group animal, and especially for males, high status within the group is the trait most worth having because it is the high-status individuals who mate the most. The importance of status to humans is obvious from the amount of money we spend on clothes, cars, homes, parties, and generally “keeping up with the neighbors.” And, conversely, low status, and expulsion from the group is most feared. ²⁸
    Since group animals usually breed more among themselves than with outsiders, ²⁹ they are more closely related to each other and share many of the same alleles and traits. This inbreeding not only enhances the cohesiveness of the group, it also makes the group genetically different from other groups and, if one group is better adapted, its members will have more reproductive success than the members of other groups. Although a group can therefore be selected, ³⁰ it is individuals that biologically reproduce, not groups, and it is the individuals within the group that is positively selected who have greater reproductive success, passing on the traits that enabled their group to be selected. (Levin, 1997, p.167). Even if a member does not himself reproduce, since he is more related to others in his group than he is to outsiders, and his fellow group members therefore carry more of his alleles than do outsiders, he nevertheless also achieves reproductive success because others in his group pass on many of the same alleles that he would pass on. (See Chap. 8). A more reproductively successful group will grow in numbers and will more frequently split into two groups than other groups do, a process somewhat analogous to asexual reproduction.
    Individuals within a group are permitted to remain in the group provided they can be expected to make a net contribution to the reproductive success of those individuals within the group that produce the next generation. The likelihood of a male successfully reproducing after he is forced out of the group is low, so low status males do their best not to anger the leader. By expelling a member, the remaining members alter the gene pool of the group and, when groups compete against other groups of the same species, those other groups become part of the environment that selects whether a group is successful. ³¹
    If an individual’s alleles cause him to act only for his own reproductive success, even when it is damaging to the reproductive success of his group, and those alleles spread throughout his group, eventually both his group and his own lineage will go extinct. The result is that each individual in a group will carry some “altruism alleles” that code for behavior that increases the group’s fitness, even though that behavior reduces his individual fitness, such as alleles for deferring to the leader for breeding and for caring for the leader’s offspring.
    Both man and other group animals are normally innately capable of suffering social control emotions, such as guilt, shame, embarrassment, depression, and remorse, in response to communications from others of approval or disapproval of their behavior. ³² These social control emotions are detrimental to the individual, but essential to the successful functioning of the group. ³³ Individuals quickly pick up the meaning of facial expressions and other signs of disapproval, and usually end up following the rules to avoid having to endure the unpleasant emotion. ³⁴
    The intra-group rules need not be the same for different groups, and behavior that produces a devastating social control emotion in an individual in one group may create no emotion or even the opposite emotion in an individual in a different group. ³⁵ The group’s culture (i.e., information that is not inherited) programs and activates these emotions, inducing an individual to alter his behavior so that he benefits others in his group, even though that may reduce his personal fitness. ³⁶ Nevertheless, he accepts, and often vehemently defends, the culture of his group because an attack on his culture threatens his acceptance as a member of the group. ³⁷ If particular cultural rules enable a population to better compete with others populations, then individuals in that population who do not feel guilt, shame, or remorse when they break those rules (i.e., sociopaths) will be eliminated from that population, and the only individuals who remain in that population will be those that inherit the propensity to feel the emotions that induce them to follow the rules. Since survival in the colder north depended more on following rules than in the tropics, individuals in northern populations should have more of those social control emotions. There is some evidence that Africans are less controlled by those emotions, which may contribute to their higher crime rate.

1. The formation of the Isthmus of Panama 3 to 3.5 mya, isolating the Pacific and Atlantic Oceans, changed ocean currents, cooling Europe. (Arsuaga, 2001, p. 115). Back

2. Catastrophes other than climatic catastrophes also changed man’s evolution. A contemporary example is a mutation, the delta 32 deletion of the CCR5 receptor gene, that occurred in some northern Europeans, which enabled them to survive the bubonic plague during the Middle Ages, when hundreds of thousands of their countrymen died; more recently, it offers some protection against AIDS. (Guilherme, 2002). Back

3. The only major one occurred in Siberia in 1908 and it had little effect on humans. Back

4. Temperatures are estimated to have dropped about 30°C (54°F) for weeks or months in the Northern Hemisphere. (Rampino, 1988). During the Ice Age of 30,000 to 12,000 ya, the climate in Germany was quite cold and the Mediterranean Sea had the climate the Baltic Sea has now. Back

5. There were limited glaciers around Kilimanjaro and Mount Kenya. (Hasterath, S., The Glaciers of Equatorial East Africa, 1984). Back

6. (Ambrose, 1998). "The scarcity of artifacts in the loess bed that overlies the [central Asian plain] suggests that much of the plain was abandoned between 73,000-55,000 years ago." (Hoffecker, 2002, p. 19). Back

7. In Asia, the cold selected for neoteny. (Chap. 6). Back

8. Even when sea levels were lowest, there was still at least 50 km (31 miles) of open ocean between Australia and Asia. (Sykes, 2001, p. 285). Back

9. (Weston, 2007). An excellent book on sexual dynamics is The Woman Racket, by Steve Moxon. Back

10. The general rule is that the sex that invests less in raising the offspring, usually the male, will pursue the opposite sex, who will do more of the selecting. In some species of seahorses, however, the male incubates the young, a costly investment, and he is pursued by the females and he does the selecting. (Allman, 1994, p. 114). Similarly, female phalaropes (ducks) pursue males because the males brood the eggs. (Rising, G. “Nature Watch,” Buffalo News, Oct. 21, 2007). A man who must spend a lifetime caring for a wife and his children will be more pursued by women, and will do more selecting than a man who incurs no such obligation. Back

11. (Lynn, 2006a, p. 224). “Women perform 80 percent of daily work” in Africa. (Wax, 2003). Polygyny is also common in Africa, with the best men having the most women, but this is mostly economic as the wives do the work and are self-supporting and have access to many other men. “In Africa, feminist groups don't protest that men don't let them do work, they protest that men leave them most of the work.” (Sailer, S. Oct. 9, 2007 comment on Megan McArdle, The Atlantic.com, “Why is Africa So Screwed Up?”). Agriculture made women more self-sufficient, making additional wives affordable, which lead to polygeny. That left many men without women, increasing the selective power of women, resulting in the enhanced physical attractiveness of African men and the diminished attractiveness of African women. "The traditional Zulu does not make physical beauty a first priority or even an important qualification in a wife…" (Vilakazi, 1962, p. 59). Back

12. Women would not spend billions of dollars on clothes and cosmetics if men were not selecting them for beauty. Back

13. "There is some ambivalence in societies where women do most of the agricultural labor. In such a context, wives tend to be chosen for their ability to work outdoors, especially in the sun, and less weight is given to other criteria, like physical beauty. This is true in most agricultural societies of sub-Saharan Africa and in New Guinea." (Frost, 2005). “Among the Nigerian Wodaabes, the women hold economic power and the tribe is obsessed with male beauty; Wodaabe men spend hours together in elaborate makeup sessions, and compete - provocatively painted and dressed, with swaying hips, and seductive expressions in beauty contests judged by women.” (Wolf, 1991; also Hunt, 1864, p. 20). Now that white women are becoming financially independent, they are also placing more emphasis on male appearance. (Moore, 2006). In time, if whites survive, white men will also become better looking and white women less attractive. Back

14. In addition to meat, males also provided protection from predators and other males. This implied pair-bonding contract is strongest when women are least capable of acquiring food for themselves, i.e., in the northern climates. When a population is starving, there is a widespread trading of sex for food. (e.g., Keeling, 1947, pp. 57-59). Back

15. Any man besieged by women is likely to find the temptation to be a cad irresistible since the more women he impregnates, the more reproductively successful he is likely to be. Women are enthralled by cads because they seem to be genetically superior, as evidenced by the quality of the music they can create, their athleticism, their looks, confidence, etc. And, if other women want cads, the sons they have with a cad may also be more reproductively successful. Wealth, in addition to providing assurance of support, can be used to create an effective “bluff,” so a man can present himself as being of better genetic quality than he is. Ditto for a woman and her makeup, clothing, and grooming. Back

16. (Buss, 2008). She can obtain all those qualities in a man and still keep Joe Sixpack’s pay check by successfully cheating, so men select for faithfulness in long term relationships. (Salter, 1996). Back

17. Actually, both sexes select for intelligence, though women more so. (Rosenberg, 2008). That brains increased in size from the beginning of hunting means that the possessors of larger brains were more successful with the ladies, probably because of the additional meat that more intelligent men were able to acquire and trade for sex. (Coon, 1962, pp. 78, 86). Women often say they want a man with a good sense of humor, and humor also correlates well with intelligence. Back

18. It also correlates well with a lower crime rate, less psychopathy, and other traits desired by most females. Back

19. “Power is the ultimate aphrodisiac.” (Henry Kissinger). The drive for status is hard wired into the human brain. (Zink, 2008). Back

20. (Coon, 1962, p. 93). By conquest, Genghis Khan had about 800,000 times the reproductive success of the average man of his age; about 8% of the men (16 million men, 0.5% of all the men in the world) in a large area of Asia carry his Y chromosome. (Zerjal, 2003). Back

21. During war and occupation, there is often no penalty and rape is common. (Keeling, 1947, pp. 49-57). Back

22. The more polygynous a society is, the more men there will be who cannot find a woman. Almost all suicide bombers are single Muslim men because Islam permits polygyny and promises 72 virgins if a believer dies for the faith. The dearth of women caused by polygyny also led to the importation of female African slaves. Back

23. Both sexes may be able to achieve more reproduction success by not putting all their germ cells in one basket, so to speak, but that is usually easier for a man to do. With the courts favoring women much more than they used to (“Why get married? Just find a woman who hates you and give her your house.”), the cost to a man has increased, perhaps discouraging marriage. Back

24. This suggests that the more selective the sexes are, the higher the quality of the population will be and, conversely, the more indiscriminate sexual relations are, the faster the population will degenerate. Back

25. And beauty correlates well with fertility, both tending to maximize at age 24.8. (Johnston, 2006). Since younger women are more fertile and more capable of raising children, men prefer youthful women and most marriages are younger woman – older man. Women are more neotenic than men because men have selected them for youthfulness. Light skin is also associated with youth (and dark skin) with masculinity. In one study, the skin of white women was 15.2% lighter than the skin of white males, and the skin of black women 11.1% lighter than the skin of black men. (Bauman, 2004). Back

26. Good looks are less important to women, provided they need men to provide food and other resources, because their reproductive success is limited if they don’t have access to resources; male reproductive success, however, is limited by access to females. (Lewin, 1998, p. 162; McNulty, 2008). Also see (Etcoff, 1999; Barash, 1997; Small, 1995; Botting, 1995). Fifty-six cell divisions are required to go from a human egg to an adult and good genes are required to accomplish that with a minimum number of errors. (Schwartz, 1999). Back

27. (Frost, 2006). Beautiful people have more female children. (Kanazawa, 2007). Why? Because people who carry alleles for both beauty and more female children have greater reproductive success than people who carry alleles for only beauty or only more female children. Women pass on their beauty to their daughters, but men don't pass on their good looks to their sons. Why? Because women select men more for traits other than good looks. (Cornwell, 2008). Back

28. Groups develop rituals, beliefs, customs, language, and apparel to induce individuals to identify with their group and to discourage desertion. Back

29. In group animals, even though the loss of members weakens a group, one or both of the sexes often leaves the group at sexual maturity and joins a different group. This may be to reduce inbreeding, to spread the group’s alleles, or to acquire new alleles that may have arisen in other groups. In most primates that live in groups, it is the adolescent males that leave. Since males compete for females, males leaving reduces intra-group strife, though it means that many young males will never find mates. The absence of a male does not reduce the reproductive success of the group much because a single remaining male can impregnate many females. In gorilla, chimpanzee, and human groups, however, it is the females who leave the group (Allman, 1994, p. 124; Wrangham, 1996, p. 24; Arsuaga, 2001, p. 164; Also see (Bonobo Initiative and De Waal, 1997, p. 60), sometimes by being captured by males from other groups. About 70% of human societies are “patrilocal” (male stays, as opposed to “matrilocal,” female stays). (Burton, 1996). (The fact that humans are patrilocal may help explain the higher miscegenation rate of white females.) The most obvious reason for this difference is that gorillas, chimpanzees, and humans engage in more intense inter-group competition (Van Vugt, 2007), i.e., war, and males are required to defend the group’s territory. Groups without adult males would simply have their females and territory taken by males in other groups. Thus, the success of the group is so important to the survival of humans that the advantages of retaining females in the group are sacrificed to achieve it. (A pecking order (“dominance hierarchy”) reduces male-male competition for females within a patrilocal group; also, males in the group are related and carry many of the same alleles; see Chap. 8). Back

30. (Wikipedia, “Group selection”; Wilson, 2007 & 2008). Groups exist only because they are adaptive (Chapter 4, Rule 10, corollary 1) and, if they are adaptive, they must be selected. Also see “Dual Morality,” p. 284. Back

31. (Levin, 1997, p. 74). Here is a remarkable example of the power of selection on groups: In North America there are southern cicadas that emerge from the ground every 13 years and northern cicadas that emerge every 17 years. Why such weird numbers? Well, they are both prime numbers, which means the southern and northern cicadas will emerge the same year only in once every 221 years (13 x 17 = 221). Thus, any predator that relies upon eating cicadas for survival will have great difficulty increasing its numbers at the same time that the cicadas emerge. (Patterson, 1999, p. 82). In other words, initially there were many cicada groups with many different cycles. Over time, only those groups that had long cycles that did not frequently coincide with the cycles of other groups were able to avoid predators and survive. Back

32. For example, 200 years ago, calling someone a "racist" would have generated no emotional response. Today, the name-caller knows he is being verbally agressive and the other person knows he is under attack; their amydalae respond by jacking up their adrenalin. An individual who lacks the capacity for these social control emotions, i.e., a sociopath, can nevertheless pretend to have them and, at the same time, not have his actions impeded by them. (Stout, 2005). Back

33. In addition to reducing intra-group conflict and increasing intra-group cooperation, they also reduce the “tragedy of the commons,” where individuals within a group exploit resources beyond the level at which the resources are self-sustaining, which is detrimental to the group as a whole. (Wilson, 2007). Although Wilson (2007) states, “Selfishness beats altruism within single groups. Altruistic groups beat selfish groups,” this is not always true as other members of the group can and do punish selfish members. Back

34. Guilt is self-punishment for not following the group’s rules and shame induces submission to those rules. See various papers by Robert Trivers. Both are genetically-predisposed emotions. Sociopaths do not feel these emotions, because they lack alleles for them or those alleles have been turned off. Back

35. For example, in “respectable” society, getting drunk is disgraceful, but sailors may take pride in it. Back

36. (Plutchik, 1980). Another group animal, the dog, is also said to have some of those emotions. Back

37. We are the product of our place and time, “imprinted” with the beliefs of those around us. We fear contradictory views because they threaten our acceptance within our group. To avoid expulsion, we sacrifice our objectivity and fervently believe and rationalize obvious falsehoods. Back