Sex, Gender, Evolution, and Social Constructivism
Although not germane to the hypotheses of this study, researchers have considered the influence of sex/gender to be an important influence in predicting helping intentions (e.g., R. Russell, personal communication, November 1, 2000). Sexual selection, sexual roles, and other issues related to sexuality have great consequences in the process of evolution. A full discussion of this topic is beyond the scope of this manuscript, however those issues most directly relevant to the hypothesized predictors of helping intentions will be addressed.
Parental investment theory and gender specific personality characteristics.
Trivers' (1972) theory of differential parental investment explains why males court females in most species. In biology, the differentiation of sexes is based on the relative size of their biological contribution to offspring. Those who contribute the greater portion are considered female, those who contribute the lesser portion are considered male. In humans, the mother provides the cytoplasm, pregnancy and breast milk.
The increase in brain size experienced by our ancestors also resulted in a more difficult childbirth due to the enlargement of the skull. In order to compensate for this difficulty, childbirth occurred earlier in development, and human infants were born relatively immature as compared to other animals. Although other animals became more and more independent within a matter of months, humans remained dependent on their parents at least until their teenage years (Fisher, 1992). Because women breast-fed infants, they were the likely candidate to care for small children, and became increasingly more burdened by child care as the span of development elongated. In humans, females do not only make the greater pre-natal contribution of resources, they make the greater post-natal contribution of resources as well.
Because females have a much lower reproductive ceiling than males, the female strategy is quality over quantity. The basic female strategy is one of intensive care for each member of a relatively small number of young. Males vary more in their reproductive success than females, and are able to have many more offspring than females. By expending a relatively large part of their reproductive effort on mating, males of most species devote rather little in comparison to parental care (Daly & Wilson, 1978). Each sex became specialized and more adapted to the types of tasks they performed. The tasks that men performed, such as hunting and defense of territory, are characterized as spatial, silent and aggressive. On the other hand, women verbally interacted with their children and the other women of the group while they foraged for edible plants (McGrew, 1981).
In addition to characteristics that both males and females value in a potential mate, including kindness, understanding, and intelligence (Kenrick & Simpson, 1997), humans also have gender specific criteria for sexual selection. In a study of 37 cultures on six continents and five islands, Buss (1989) found that women value prospective male suitors on a cluster of characteristics related to resource potential: good financial prospects, ambition, industriousness, older age, and emotional maturity. On the other hand, men value potential female partners in terms of fecundity, the ability to produce and care for children.
Carol Gilligan (1982) proposes that women have outstanding sensitivities in interpersonal relationships. She found that women cast themselves as actors in a web of attachments, affiliations, obligations, and responsibilities to others. Women also seem to have a higher need for affiliation and a longer attention span for conversation. The adaptations to interpersonal situations may make women more sensitive to subtle cues when dealing with others. Women are better at being able to read the emotions contained in facial expressions, even when looking at pictures of people (Pool, 1994). On average, women also read context and all sorts of peripheral non-verbal information more effectively than men (Hall, 1984; McGuinness, 1976).
Social constructivist challenges to evolutionary explanations for gender characteristics.
Recently, the social psychologist Alice Eagly and others have criticized the evolutionary explanation that sex differences result from specific adaptations to the different problems faced by females and males in the environment of evolutionary adaptation. Eagly (1997) proposes a cultural explanation for human gender characteristics based on a division of (non-childbirth) labor. Men monopolize the means of production and exhibit social dominance in the societies under study (Eagly & Wood, 1999). Thus, women are only maximizing utility by selecting men with substantial resources or resource potential, given the constraints of society.
Following this argument, the favored attributes could be expected to reverse gender assignments in cultures where females exhibit social dominance. However, the pattern is consistent in societies where women have more economic resources than men (Ardener, Ardener, & Warmington, 1960). In fact, when women hold positions of high status and economic power, their preference for high status men appears to increase in strength (Buss, 1989; Townsend, 1989; Wiederman & Allgeier, 1992). Also, men in all cultures examined to date tend to seek mates near their own age when they are young, then seek and find progressively younger women as they age. Yet, contrary to socio-cultural power explanations for mate selection criteria, teenage males are attracted to substantially older women (Kenrick & Simpson, 1997).
In other animal species, a reversal in gender roles in sexual selection does occur. Seahorse females compete for the attention of males and typically have brightly colored ornamentation, in contrast to the dull males. Male seahorses have a special pouch that holds infant seahorses as they mature. In species where males make the greater parental investment, such as seahorses, certain frogs, the Mormon cricket, and several species of marsh birds, females compete for access to males (Crawford, 1998, Trivers, 1985).
An evolutionary approach to psychology does not exclude social and cultural influences. The context of a person’s social and physical environment is seen as important in guiding if and how genetically based predispositions will be expressed as behaviors (DeKay & Buss, 1992). For example, the resource environment during childhood development can influence the type of mating strategy exhibited (Buss, Haselton, Shackelford, Bleske, & Wakefield, 1998). One should be suspicious of any theory that attempts to explain complex social phenomena through a single causal relationship. Even psychologists with a strong constructivist orientation see that proximate causes of gender differences in emotional expressiveness, such as socialization and status/power differentials, cannot be understood without the context of genetic factors (e.g., Brody, 1993), in other words, the influences of adaptations from our evolutionary history.
The contention between the evolutionary and social constructivist approaches lies in whether adaptations from natural and sexual selection can be used to explain non-physical sex differences (Eagly & Wood, 1999). Social constructivists acknowledge the role of biology in creating size and upper body strength disparities between human men and women, but otherwise see people as a tabula rasa that can be edited by socialization into whatever role society desires them to fill. Resolution of this controversy is outside the scope of this project. Readers are encouraged to explore the literature that further supports the relevance of evolution to gender issues (e.g., Buss, 1989, 1998; Daly & Wilson, 1978; Darwin, 1871; Fisher, 1992; Kruger, In Press a; Low, 1979; Malamuth & Heilmann, 1998; Miller, 1998; Pool, 1994; Ridley, 1994; Silverman & Phillips, 1998; Trivers, 1972; Wiederman & Allgeier, 1992). Hypotheses for gender based differences will be compatible with both an evolutionary and social constructivist approach, because they entail a replication of current research findings with regard to emotions and helping intentions.