In their book Homicide, Martin Daly and Margo Wilson put forth a theory that challenges human societies common notion of human sexuality. They do this in an attempt to bring about a better understanding of homicide and male aggressiveness. According to Daly and Wilson, males instigate the overwhelming majority of “dangerous altercations” and they contend that this is due to “status competition.” Status competition is the idea that males must aggressively compete for sexual access to females in order to pass on their genes.
Daily and Wilson cite the work of Charles Darwin, who in 1859 published a famous work on the theory of natural selection.
The concepts presented in his book were later elaborated in his second work, which dealt with the concept of “sexual selection.” Sexual selection according to Darwin’s theory, was based on the observation that not all evolutionary adaptations serve a survival function; that in many cases, “a trait might be penalized by ‘natural’ selection and yet win out by ‘sexual’ selection.” Darwin argued that surviving and living a long life did not ensure reproductive success and therefore an animal’s goal of longevity is secondary to its goal of passing on its genes through procreation. These ideas form the foundation for Martin Daly and Margo Wilson’s theory.
Daly and Wilson also refer to the research done by a British geneticist named A.J.
Bateman to strengthen their arguments for the idea of status competition. Bateman’s research focused on lab experiments done on Drosophila or fruit flies. The experiments consisted of taking fruit flies with “distinct genetic markers” and placing them in jars. It was made sure that each jar contained an equal number of males and females. The jars were then put under observation. Bateman noticed that there was a difference when he compared the reproductive success of the females to the success of the males.
According to Bateman’s research a female fruit fly could expect to have about 60 to 80 offspring regardless of the number of male fruit flies she copulated with. However the reproductive success of a male fruit fly depended on the number of females it had mated with. “Those who copulated with one female produced about 40 young, those who copulated with two produced about 80, and so forth.” Bateman also notes the difference each sex of fruit fly could expect to produce-females could expect to have about the same amount of offspring, whereas some males had a great number of offspring (far above average) while others failed to produce at all. In general males had a much wider range of potential offspring and therefore the males had potential for great success or complete failure. These finding prompted Bateman to conclude “selection would produce tactics of male mating competition, as well as an undiscriminatory eagerness in the males and a discriminatory passivity in the females.
Daly and Wilson claim that the conclusions made by Batman on fruit flies reproductive condition also hold true for Homo sapiens. According to Daly and Wilson, human females have a lower maximum number of offspring they can produce when compared to males. Females also have a much smaller range of mating outcomes when compared to males. Daly and Wilson cite the work of Robert Trivers to corroborate this idea. According to Trivers, the key to understanding the difference between male and female fruit flies, as well as humans, is by determining the amount of parental investment given by either sex. According to the their theory females make the largest parental investment and consequently can not expect to increase her chances of passing on her genes by mating indiscreetly.
Women typically must “invest” time in pregnancy as well as feeding the child (Female fruit flies investment comes in the form of producing eggs). Whereas a male increases his chances of passing on his genes with each female he mates with, due to his relatively small parental investment. Because male success is determined by the amount of access he has to females, males must compete for access to females much more than females must compete for access to males. This competition, according to the theory, makes the “winners win bigger, and the losers…more likely to be total losers.”