The Handy Psychology Answer Book. Lisa J. Cohen

is Social Darwinism?

      Social Darwinism refers to a loose group of theories that arose in the late-nineteenth and early-twentieth centuries, following publication of Charles Darwin’s theory of evolution. This was a time of European imperialism, intense immigration into the United States, and growing masses of urbanized poor due to the industrial revolution. Thus, social prejudices spread among the European and American elite who convinced themselves that the conquered and the impoverished were somehow deserving of their status. Likewise, the idea of survival of the fittest was used to justify this viewpoint. Darwin did not intend evolution to be racist or a justification of social inequity. His theory was an explanation of how animals adapted to their environments. It was not a moral prescription for society. But his work was misinterpreted to mean that only the strongest and most worthy will survive and that social disadvantage was a reflection of genetic inferiority. Galton’s theory of eugenics is a good example of Social Darwinism.

      How do evolutionary theorists understand altruism?

      Altruism, which involves helping others at some cost to the self, has long been a puzzle to evolutionary theorists. How is altruistic behavior evolutionarily adaptive? It is certainly common enough in the animal world. Worker bees and drones live their entire lives in service to the queen bee. They do not even reproduce. Alarm calls are also altruistic. When an animal sounds the alarm, warning others of the presence of a predator, the animal increases its visibility to the very predator it is warning against. Likewise, altruistic behavior is widespread in human beings. We give money to charity, take care of other people’s children, and may even donate a kidney to a relative in need.

      Although altruistic behavior may cost the individual animal, it may still confer reproductive success if it helps other animals that share the same genes. Even if performing altruistic behavior may not help the individual animal pass on his or her genes, it can help the animal’s relatives pass on their shared genes. Thus, we would expect altruistic behavior to be most common among close relatives, which is universally the case. What is also found is that the cost and risk of altruistic behavior that an animal is willing to perform decreases as the biological relationship grows more distant. Think about it. Most of us are willing to donate used clothes to children in another country. This is a low cost and low risk investment. But would you be willing to sell your house and donate the proceeds to a complete stranger? Would you be willing to donate a kidney to a stranger? Or would you be more likely to donate your kidney to your sister, especially if she was likely to die without it?

      Helping others at some cost to one’s self, as when donating blood, is known as altruism. Scientists, assuming that evolution was based on self-preservation, have long wondered what the evolutionary advantages of altruism could be.

      How do evolutionary theorists understand sexual behavior of males and females?

      Because sexual behavior has such direct impact on reproductive success, sociobiologists have given a good deal of thought to the evolutionary significance of various forms of sexual behavior. In many species, males and females may have different strategies for reproductive success. Females devote an enormous amount of time and energy to bearing and raising their young. The more complex the species, the more this is the case.

      For example, humans, chimpanzees, and dogs provide much more maternal care than turtles do. Therefore, it is in the evolutionary interest of many females to be highly selective in their choice of mates and to seek males that can contribute to care of the young. Males, on the other hand, do not bear young and are not physically bound to the care of the young. They can develop a wide array of successful reproductive strategies. They can inseminate a large number of females but give little resources to the care of their offspring (e.g., buffalo, wildebeests), or they can inseminate fewer females, have more offspring with them and give much more time and energy to the care of their young (e.g., trumpeter swans, gibbons). Some males (e.g., gorillas, fur seals) compete for exclusive access to a group of females, devoting considerable energy to protecting their harems from encroachment from rival males.

      Are men inherently polygamous?

      Across history, human males have exhibited all of the above reproductive strategies. They are monogamous, promiscuous, or polygynous. Some even have harems. Whichever strategy is selected is dependent on numerous environmental contingencies, such as population density, scarcity of resources, culture, religion, social status, etc. While human females are not immune to the temptations of multiple partners, polygamous societies with polygynous marital patterns (men with multiple wives) are far more common than those with polyandrous marital patterns (women with multiple husbands).

      What is sexual selection?

      Because females invest so much more energy into reproduction than males do, females are high-energy resources and hence very valuable to males. Consequently males are likely to evolve strategies to compete for them. Sexual selection means that any physical trait or behavioral pattern that increases access to mates will be evolutionarily advantageous. Sexual selection is most pronounced in polygamous species, where a sort of winner-take-all system results in clear winners and losers.

      One of the most common competitive strategies for males involves physical size and strength. Across many, many species larger males have more offspring. Likewise dominant males can jealously guard access to multiple females, creating harems that they defend aggressively. However, in these circumstances non-dominant males will be excluded from access to females. Therefore, the non-dominant males have developed alternative strategies. In several species, including stickleback fish, prairie chickens, and elephant seals, smaller and non-dominant males disguise themselves as females to gain access to the dominant males’ territory and the females within.

      These strategies work in direct male-to-male competition. But females are also often highly selective. Males have to compete for female favor as well. It is likely that elaborate display rituals, which are evident in many birds, reflect behaviors evolved to enhance female preference. Such rituals often do two things. They can advertise the males’ size and strength, often in exaggerated form. They can also attempt to persuade the female of the resources the male can make available for child rearing. For example, male scorpion flies give a high calorie gift to their prospective mates. Female scorpion flies, in turn, prefer males who make larger gifts. Perhaps the tendency for human males to buy women expensive jewelry and take them out to high-priced restaurants is a related phenomenon.

      In the competition for sexual partners, many species have adapted amazing strategies. Peacocks, for instance, make stunning displays of their feathers to attract peahens. Humans, too, have evolved their own competitive strategies.

      So, is evolution only about competition?

      Natural selection works on the comparative advantage of genetic traits. Perhaps because of this, evolutionary theorists have tended to emphasize the competitive nature of social relations. But this paints a very incomplete picture. Social behavior in all highly social animals involves much more cooperation than competition or antagonism. If social life was entirely a Hobbesian free-for-all, there would be little reason for humans and other animals to seek each other out. Just as evolution results in competitive and aggressive behavior, it also results in the capacity for strong social bonds, parental devotion to children, affection, cooperation, empathy (in humans at least), and many other traits that support cohesive social groups.

      Do females compete for males?

      Although male-to-male competition can be very dramatic in the animal world and consequently has received more attention from sociobiologists, female-to-female competition certainly exists. Some female birds roll other females’ eggs out of the nest or otherwise interfere with their reproduction. In complex social groups, females can compete